### 1 OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION 

### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

March 6 , 2015

PC Code: 121001
DP Barcode: 424581

MEMORANDUM

SUBJECT: EFED Registration Review Problem Formulation for Sethoxydim

FROM: Christina Wendel , Biologist

James Lin, Environmental Engineer
Environmental Risk Branch 2 Environmental Fate and Effects Division ( 7507P)

REVIEWED Elyssa Arnold, Biologist

BY: Environmental Risk Branch 2

Environmental Fate and Effects Division ( 7507P)

THROUGH: Brian Anderson, Branch Chief

Environmental Risk Branch 2 Environmental Fate and Effects Division ( 7507P)

TO: James Parker , Chemical Review Manager

Neil Anderson

, Branch Chief Risk Management and Implementation Branch 1
Pesticide Re

- e valuation Division (7508P)

### 2



## Table of Contents

1. Executive summary

................................ ................................ ................................ ................. 3

2. Introduction

................................ ................................ ................................ ............................. 4

a. Mode of Action

................................ ................................ ................................ .................... 4
3. Use Characterization

................................ ................................ ................................ ............... 4

4. Conclusions from Previous Risk Assessments

................................ ................................ ..... 11

a. Ecological Risk Assessment

................................ ................................ .............................. 11
b. Drinking Water Exposure Assessments

................................ ................................ ............. 13

c. Clean Water Act Programs

................................ ................................ ................................ 13
5. Environmental Fate and Transport

................................ ................................ ........................ 13

a. Transport and Mobility

................................ ................................ ................................ ...... 13
b. Degradation

................................ ................................ ................................ ........................ 14

c. Transformation Products

................................ ................................ ................................ .... 15

6. Receptors

................................ ................................ ................................ ............................... 20

a. Effects to Aquatic Organisms

................................ ................................ ............................ 21
b. Effects to Terrestrial Organisms

................................ ................................ ........................ 23

c. Ecological Incidents

................................ ................................ ................................ ........... 25

7. Exposure Pathways of Concern

................................ ................................ ............................ 26
8. Analysis Plan

................................ ................................ ................................ ........................ 26

a. Stressors of Concern

................................ ................................ ................................ .......... 27
b. Measures of Exposure

................................ ................................ ................................ ........ 27

c. Measures of Effect

................................ ................................ ................................ ............. 28
d. Endangered Species Assessments

................................ ................................ ...................... 28

e. Endocrine Disru ptor Screening Program

................................ ................................ ........... 28

9. Preliminary Identification of Data Gaps

................................ ................................ ............... 28

a. Environmental Fate

................................ ................................ ................................ ............ 28
b. Effects

................................ ................................ ................................ ................................ 29
10. References

................................ ................................ ................................ .......................... 39

a. Submitted Environmental Fate Studies

................................ ................................ .............. 3 9
b. Submitted Ecological Toxicity Studies

................................ ................................ .............. 43 APPENDIX A. SLUA Summary Table for Sethoxydim

................................ .............................. 50 APPENDIX B. Sethoxydim Ecotoxicity Data

................................ ................................ .............. 52 APPENDIX C. Sethoxydim Incidents

................................ ................................ ......................... 59 APPENDIX D. SIP & STIR Inputs and Outputs for Sethoxydim

................................ ................ 62

### 3



## 1. Executive summary

The Environmental Fate and Effects Division (EFED) has completed the preliminary problem formulation for the ecological risk, environmental fate, endangered species, and drinking water assessments to be conducted as part of the registration review of setho xydim

. The problem
formulation describes the methods planned to be used during the completion of drinking water and ecological risk assessments in support of registration review and provides an ove rview of the environmental fate, ecological effects

, potent ial risks associated with the use, and uncertainties unique to the risk assessment of sethoxydim

. This document also identifies additional studies that would be beneficial to the conduct of an ecological risk assessment.

A number of ecological risk assessments have been conducted on sethoxydim. Conclusions from
those assessments are that sethoxydim do es not result in level

- of

- concern (LOC) exceedances for aquatic animals or aquatic plants

. Risks exceeding the LOC were id entified for mammals and terrestrial monocot plants . There are chronic dose

- based LOC exceedances for multiple size
classes of mammals consuming a variety of dietary items, and e xceedances occur even with a single application of sethoxydim. Risk exceedin g the LOC may affect l isted monocot grass species at >1000 feet and non

- listed monocot grass species at up to 509 feet from field s treated with sethoxydim . R isks to bees are uncertain in the absence of data; therefore, EFED
recommends that additional data be requested to allow for a more comprehensive evaluation of potential effects to honey bees. EFED will evaluate those data when they are submitted and will work with PRD to address any risks of concern identified by those data. In addition to the need

f or honeybee data, data is needed to evaluate the terminal degradate, sulfone.

The following are the needed data and major uncertainties for sethoxydim :

Data Needs

 Ecotoxicity Data

o OCSPP 850.1300: Freshwater invertebrate life

- cycle toxicity study using TGAI

o OCSPP 850.1350: Saltwater invertebrate life

- cycle toxicity study using TGAI

o OCSPP 850.1400: Saltwater fish early life

- stage toxicity study using TGAI

o OCSPP 850.2100: Acute Oral Toxicity with passerine species

o OCSPP 850.3030: Honey bee Toxicity of res idues on foliage

o OECD TG 213 and Non

- guideline special studies: Honey bee adult acute and chronic oral toxicity studies

o OECD TG 237 and Non

- guideline special studies: Honeybee larval acute and chronic oral toxicity studies

o Non

- guideline special studies: Field trial measuring residues of sethoxydim in pollen and nectar

o Special study OECD TG 75 and OSCPP 850.3040: Semi

- field testing for pollinators and Field testing for pollinators (both studies that are conditionally required based on the results of the Ti er I

– laboratory based studies listed above; if needed these additional field studies will be discussed pending the results of the acute and chronic adult and larval oral toxicity studies to honey bees).

### 4 o OCSPP 850.41 0 0 : Terrestrial p lant seedling e mergen ce toxicity study with current market TEP (typical end

- use product). A dditional information is needed to
determine if the stud ies were conducted with the current market TEP for

monocots and dicots. If not, a new Tier II seedling emergence study using the current market TEP is needed, and an acceptable Tier I test (at least is needed, unless a Tier II study is triggered for dicot plant species).

o OCSPP 850.4150 : Terrestrial plant v egetative vigor Tier II toxicity study with (dicots and one additional spec ies of monocots ) to fulfill guideline. The only
available vegetative vigor data for dicots was conducted with 95.4% a.i., and not
with TEP stated i n the CFR

. Therefore, t e rrestrial plant toxicity with the current
market TEP is still needed for dicot species

. In addition, to fulfill the guideline, one additional monocot species is also needed from a different Family (the three species tested represent Family Poaceae (grasses) only ).

o Degradate Toxicity

– Sulfone (terminal degradate , M2

- SO 2 

### )

 N on

- guid eline study: aquatic vascular plant toxicity study with a grass species



## 2. Introduction

Sethoxydim is used post

- emergence for selective control of annual and perennial grass weeds in broadleaf crops. Two end

- use formulations containing sethoxydim are current ly registered for
use in the United States. Sethoxydim was previously assessed at the time of t he Reregistration

El igibility Decision (RED) in 2005 (USEPA, 2005), and a new use assessment was completed in December 2014 (USEPA, 2014).



## a. Mode of Action

Sethoxydim is a member of the c yclohexanedione class of chemicals. The mode of action for
this herbicide is l ipid b iosynthesis i nhibition. Selectivity is shown to be due to the greater susceptibility at acetyl

- coenzyme A carboxylase (ACCase) of grassy sp ecies. Susceptible grassy species are killed by inhibition of the ACCase which is a key enzyme in the lipid biosynthetic pathway.



## 3. Use Characterization

Sethoxydim is a systemic herbicide which is registered for selective post

- emergence control of a wide spectrum of annual and perennial grasses. It is applied either by aerial or ground methods and is registered for many different agricultural and residential uses throughout the United
States. Two commercial available formulati ons are Emulsifiable Concentrate (EC) and Soluble Concentrate/Liquid (SC).

Table 1 lists the maximum use patterns for the labeled use sites. The table is the concise version based on the Label Use Report Package prepared in support of registration review (October 2014)

.

### 5

Table 1 . Maximum Use Patterns for Current Registered Use Sites of Sethoxydim

Use Site Formulation

Type 1 Max. Rate

(lbs a.i ./Acre) Max. No. of

Applications per Year Min.

Application

Interval Application

Methods Comments Single C.C. 2 Annual

1B. Root vegetables (except sugar beet) subgroup EC 0.4382 0.4382 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed p ost

emergence

1C. Tuberous
and corm vegetables subgroup EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed p ost

emergence

20A. Rapeseed subgroup EC 0.4382 0.8764 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed p ost

emergence

A gricultural

F allow /I dleland /
C onservation

Reserve EC 0. 4607 1.3821 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed Post

emergence

Alfalfa EC 0.4607 1.1978 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed Post

emergence

Apricot EC 0.4382 0.9214 NS NS 14 Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Artichoke EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Asparagus EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Avocado EC 0.4607 1.3821 NS NS 14 Ground

- Spray; Band Treatment, Spot Treatment, Direct Spray Non

- bearing

Beans,
Dried

- Type EC 0.4607 0.7371

NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

SC 0.3931 0.3931 NS Weed Early

Post

- emergence

Beans,
Succulent (Snap) EC 0.4607 0.7371 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Beets (Unspecified) EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Blueberry EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Borage EC 0.4382 0.8764 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed Post

emergence

### 6 Use Site Formulation

Type 1 Max. Rate

(lbs a.i ./Acre) Max. No. of

Applications per Year Min.

Application

Interval Application

Methods Comments Single C.C. 2 Annual

B rassica (H ead and
S tem )

V egetables EC 0.2764 0.5528 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Buckwheat EC 0.4382 0.8764 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed Post

emergence

Bulb Vegetables EC 0.2764 0.8292 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Caneberries EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Canola/Rape EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed Post

emergence

Carrot (Including Tops) EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Celery EC 0.2764 0.5528 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Cherry EC 0.4607 0.9214 NS NS 14 Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Citrus EC 0.4607 1.8428 NS NS 14 Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Clover EC 0.4607 1.1978 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed Post

emergence

Corn, Field EC 0.2764 0.5528
NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment,
Burndown

Treatment Weed Post

emergence

SC 0.3931 0.3931 NS Aerial

– Broadcast ; Ground

- Broadcast

Corn, Sweet EC 0.2764 0.5528
NS NS 10 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed Post

emergence

SC 0.3931 0.3931 NS Aerial

– Broadcast ; Ground

- Broadcast

Cotton (Unspecified) EC 0.4607 1.3821 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment Weed Post

emergence

### 7 Use Site Formulation

Type 1 Max. Rate

(lbs a.i ./Acre) Max. No. of

Applications per Year Min.

Application

Interval Application

Methods Comments Single C.C. 2 Annual

Crambe EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment Weed Post

emergence

Cranberry EC 0.4607 0.8764 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Cucumber EC 0.2629 0.5258 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Cucurbit Vegetables EC 0.2764 0.5528 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Date EC 0.4382 1.3146 NS NS 14 Ground

– Spray; Band Treatment, Spot Treatment, Direct Spray Non

- bearing

Dill EC 0.4382 0.8764 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Endive (Escarole) EC 0.5036 NS NS NS NS Ground

- Spray Weed Post

emergence

Fig EC 0.4607 1.3821 NS NS 14 Ground

– Direct Spray; Band Treatment, Spot Treatment, Spray Non

- bearing

Flax EC 0.2764 0.7371 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed Post

emergence

F orest P lantings (R eforestation Programs) (Tree Farms, Tree

P lantation,
ETC .) EC

0.4607 NS NS NS NS Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Before Bud
Break

SC 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Direct Spray Weed Post

emergence

Fruiting Vegetables EC 0.2764 0.8292 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Grapes EC 0.4607 0.9214 NS NS 14 Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Grasses Grown
For Seed EC 0.4607 0.9214 NS NS 14 Ground

- Broadcast ; Band Treatment, Spot Treatment.

Horseradish EC 0.4607 0.9214 NS NS 14 Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

### 8 Use Site Formulation

Type 1 Max. Rate

(lbs a.i ./Acre) Max. No. of

Applications per Year Min.

Application

Interval Application

Methods Comments Single C.C. 2 Annual

Leafy Vegetables EC 0.2764 0.5528 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Lentils EC 0.4607 0.7371 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Lettuce, Head EC 0.5036 NS NS NS NS Ground

- Spray Foliar

Melons, Cantaloupe EC 0.2764 0.5528 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Mint EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Mint/ Peppermint/ Spearmint SC 0.3931 0.3931 NS NS NS Aerial

– Broadcast ; Ground

- Broadcast Weed Post

emergence

Mustard EC 0.2764 0.5528 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Nectarine EC 0.4607 0.9214 NS NS 14 Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

N onagricultural

R ights

- O f

- W ay /

F encerows /

H edgerows EC, SC 0.1843 NS NS 1 NS Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spring,

Weed Post

emergence

N onagricultural

U ncultivated

A reas /S oils EC 0.4607 1.3821 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Direct Spray Weed Post

emergence

Okra EC 0.2629 0.964 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Olive EC 0.4607 1.3821 NS NS 14 Ground

- Band Treatment, Spot Treatment, Direct Spray, Spray Non

- bearing

Orchards (Unspecified) EC 0.0921 0.0921 NS NS 14 Ground

- Broadcast Band Treatment, Spot Treatment, Weed Post

emergence

Ornamental
Lawns and Turf EC

0.4607 0.9214 NS NS NS Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment Seedling Stage,

Weed Post

emergence, Established Planting SC 14

Peach EC 0.4382 0.9214 NS NS 14 Ground

- Broadcast; Band Treatment, Spray, Spot Treatment, Spray Weed Post

emergence

### 9 Use Site Formulation

Type 1 Max. Rate

(lbs a.i ./Acre) Max. No. of

Applications per Year Min.

Application

Interval Application

Methods Comments Single C.C. 2 Annual

Peanuts (Unspecified) EC 0.2764 0.4607 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Peas, Dried Type EC 0.4607 0.7371
NS NS 14 Aerial

– Broadcast

, Spray;
Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

SC 0.3931 0.3931 NS Aerial

– Broadcast ; Ground

- Broadcast

Peas, Succulent EC 0.2651 0.7011 NS NS 14 Ground

- Spray Weed Post

emergence

Pepper EC 0.2764 0.8292 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Pistachio EC 0.4607 1.8428 NS NS 14 Ground

- Broadcast; Band Treatment, Spray, Spot Treatment, Direct Spray Weed Post

emergence

Plum EC 0.4607 1.3821 NS NS 14 Ground

- Band Treatment, Spot Treatment, Direct Spray, Spray Non

- bearing

Pome Fruits EC 0.4607 1.3821 NS NS 14 Ground

- Broadcast; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Pomegranate EC 0.4607 1.3821 NS NS 14 Aerial

– Broadcast ; Ground

- Spray; Band Treatment, Spot Treatment, Direct Spray Non

- bearing

Potato, White/ Irish (or Unspecified) EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Prune EC 0.4607 1.3821 NS NS 14 Ground

- Spray; Spot Treatment, Direct Spray Non

- bearing

Rhubarb EC 0.2764 0.5528 NS NS 14 Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Rye EC 0.4382 NS NS NS NS Ground

- Broadcast Weed Post

emergence

Safflower EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed Post

emergence

Sainfoin EC 0.4607 1.1978 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed Post

emergence

Small Fruits EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment. Weed Post

emergence

### 10 Use Site Formulation

Type 1 Max. Rate

(lbs a.i ./Acre) Max. No. of

Applications per Year Min.

Application

Interval Application

Methods Comments Single C.C. 2 Annual

Soybeans (Unspecified) EC 0.4607 0.9214
NS NS 14 Aerial

– Broadcast

, Spray ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

SC 0.3931 0.3931 NS Aerial

– Broadcast ; Ground

- Broadcast

Strawberry EC 0.4607 0.4607 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Sugar Beet EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Sunflower EC 0.4607 0.4607 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment Weed Post

emergence

Sweet Potato EC 0.4607 0.9214 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Tobacco EC 0.2764 0.8292 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment, Spray Weed Post

emergence

Tree Nuts EC 0.4607 1.8428 NS NS 14 Ground

– Broadcast ; Band Treatment, Spot Treatment, Direct Spray, Spray Weed Post

emergence

Trefoil EC 0.4607 1.1978 NS NS 14 Aerial

– Broadcast ; Ground

- Broadcast ; Band Treatment, Spot Treatment Weed Post

emergence

NS

- Not Specified

1 EC

- Emulsifiable Concentrate; SC

- Soluble Concentrate/Liquid

2 C.C.

– Crop Cycle



### To be reflective of the public usage, SLUA (Screening Level Usage Analysis) was performed by
BEAD based on the data sources from USDA

- NASS (United States Department of Agriculture's National Agricultural Statistics Service), Private Pesticide Market Research, and California Department of Pesticide Regulation (DPR) Pesticide Use Report ing (PUR) database . If future risk refinement is needed, the SLUA information will be considered ( Appendix A

, contains the SLUA summary table for sethoxydim)

.

### 11



## 4. Conclusions from Previous Risk Assessments

a. Ecological Risk Assessment

A number of ecological risk assessments have been conducted on sethoxydim. The conclusions from the past assessments are summarized in Figure 1 and Table 2 below

. In ad dition, a summary of LOC exceeda nces are listed in Error! No bookmark name given. below.

Figure 1. Graphic Summary of Potential Risks of Current and Recently Proposed Uses

### 12

Table 2 . Evidence of Risk to Taxonomic Groups from Assessed Sethoxydim Use s

Table 3 . LOC Exceedances for Assessed Sethoxydim Uses

Effect Taxonomic Group

Birds Mammals Terrestrial

Plants Terrestrial

Inverts Fish Aquatic

Inverts Aquatic

Plants

Direct Effect LOC Exceedance

-- A √ B

-- C

-- D

-- -- --

Indirect Effect Potential E √ √ √ √ √ √ √

A Using the new, acceptable, definitive avian reproduction study; no LOCs were exceeded for acute or chronic effects
to birds (surrogates for terrestrial

- phase amphibians and reptiles).

B There are c hronic dose

- based LOC exceedances for multiple size classes and dietary items. Exceedances occur even with a single application. There are n o acute or chronic dietary

- based LOC exceedances

. C M onocot grass species may show adverse effects above the LOC from sethoxydim exposure at >1000 feet from a treated field for listed species and up to 509 feet for non

- listed species.

D No toxicity is observed in the acute studies for the adult life

- stages of honey bees. However, the toxicity to larval
life

- stage s is unknown; therefore, risk is presumed in the absence of acute and chronic oral toxicity data for larvae, and chronic oral toxicity data for the adult bees as well. Sethoxydim is systemic in plants so exposure via pollen and nectar is possible.

E Indire ct risks to all listed species cannot be ruled out due to adverse effects on terrestrial plant species. Conclusion: No Risks of Concern
Ce rtainty: High Conclusion: Risks of Concern Identified Certainty: High

Birds: Using the new, acceptable, definitive avian reproduction study

, no LOCs were exceeded for chronic effects to birds. Sethoxydim is practically

no n

- toxic to birds on an acute oral and subacute dietary basis, and no mortalities were observed at the highest
doses tested. A dditional information is needed to
refine risk conclusions for passerine species.

Fish: No acute or chronic LOCs were exceeded for
freshwater or estuarine/marine fish.

Aquatic Plants: There were no LOC exceedances for aquatic plants. Terrestrial Plants: Sethoxydim is an herbicide and will likely affect exposed sensitive non

- target plants, particularly monocot grass species (Family Poaceae ), near application si tes. M onocot grass species may show adverse effects above the LOC from sethoxydim exposure at >1000 feet from a treated
field for listed species and up to 509 feet for non

listed species. No vegetative vigor or seedling emergence toxicity data for non

- gr ass monocot species or dicot species exposed to sethoxydim typical end use

- product (TEP, Poast ® ) have been
submitted

.

Mammals: Chronic dose

- based LOC exceedances only (all uses; RQs 4.5

- 1.2); for multiple size classes and dietary items. Exceedances occur even with a single application. However, there were no acute or chronic dietary

- based LOC exceedances

. Conclusion: No Risks of Concern Certainty: Low Conclusion: Risks of Concern Identified Certainty: Low Aquatic Invertebrates: No acute LOCs were exceeded.
No chronic data is available using TGAI ; therefore there is the potential for chronic risk. However, available chronic data using a n EP for estuarine/marine
invertebrates results in no risks of concern

. Because
estuarine/marine invertebrates are more sensitive than the surrogate FW invertebrate on an acute basis,
chronic risks to freshwater invertebrates are also unlikely to exceed concern levels. Terrestrial Invertebrates: No toxicity is observed in
the acute studies for the adult life

- stages of honey bees. However, the toxicity to larval life

- stages is
unknown ; therefore, risk is presumed in the absence of acute and chronic oral toxicity data for larvae, and chronic oral toxicity data for the adult bees as well. Sethoxydim is systemic in plant s so exposure via pollen and nectar is possible.

### 13 

## b. Drinking Water Exposure Assessments

The most recent drinking water exposure assessment conducted for sethoxydim was completed
for the IR

- 4 petition on fescue, oilseeds, fruits, and vegetables (DP 418281, June 2014). The

m aximum screening exposure estimates for the residues of concern were 79.6 μg/L (1

- in

- 10

- year peak) and 13.9 μg/L (1

- in

- 10

- year annual mean) for surface water and 0.565 μg/L for ground

water.



## c. Clean Water Act Programs

The Clean Water Act requires the Agency to publish water quality criteria that accurately reflect the latest scientific knowledge on the kind and extent of all identifiable effects on health and welfare that might be expe cted from the presence of pollutants in any body of water, including ground water. While these recommended criteria do not, in themselves, impose any requirements, states and authorized tribes can use them to develop water quality standards. An Aquatic Lif

e Ambient Water Quality Criteria document has not been published for sethoxydim (see url: http://www.epa.gov/waterscience/criteria/ ).

The Office of Pesticide Programs (OPP) publishes aquatic life b enchmarks for freshwater species based on toxicity values for the most sensitive species from the most recent risk assessments. However, aquatic life benchmarks have not been published for sethoxydim (see url: http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm#benchmarks ). Any data submitted or otherwise located as part of the registration review process may be used to update aquatic life ben chmarks if applicable.

Sethoxydim is not identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act, based on information provided at http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=88
5 . No Total Maximum Daily Load (TMDL) criteria have been developed for sethoxydim, based on information provided at http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id =885&p_pollutan t_group_name=PESTICIDES

.


## 5. Environmental Fate and Transport

a. Transport and Mobility

Sethoxydim is a highly soluble compound (4700 mg/L in pH 7 water) with a low octanol/water partition coefficient (log K ow 

### is 1.65). The calculated bioconcentration factors ( BCF ) for

s ethoxydim and total residues were 7X, 25X, and 21X for edible, nonedible, and whole fish, respectively. Depuration was fast, with a half

- life of 3.6 days. For these reasons

, bioaccumulation is not likely to occur. Also, due to its low vapor p ressure (1.6x10

- 7 

### mm Hg) and Henry's Law Constant (1.47x10

- 11 

### atm

- m3/mol), s ethoxydim is not expected to be volatile under
field conditions or from water.

### 14

Based on batch equilibrium experiments, s ethoxydim and its transformation products, M2

- SO 2 

### , M

- SO, M

- SO 2 

### , and M 2

- SO, were determined to be mobile to very mobile in sterile (autoclaved) sand, sandy loam, sandy clay loam, silt loam, and clay loam soils. Freundl ich K d 

### values were
<1.00 for s ethoxydim and its transformation products M

- SO and M

- SO 2 

### . The F reundlich K d 

### values for M2

- SO and M2

- SO 2 

### ranged from 0.06 to 9.12. The only unsterilized soils were used

on M2

- SO 2 

### , for the reason that M2

- SO 2 

### is thought to be the most stable among test compounds and it is the terminal degradate. The Freundlich K d 

### values of M2

- SO 2 

### with non

- sterilized soil are 0.12, 2.89, 0.78, 5.64, and 9.42, respectively for sand, sandy loam, sandy clay loam, silt loam, and clay loam.



## b. Degradation

Sethoxydim hydrolyzes at moderately rapid rates at low pHs, but is more stable at high pHs. The
calculated half

- lives are 8.7, 155, and 284 days in pH 5, 7, and 8.7 solutions, respectively. The major observed hydrolysis transformation product is M2

- S or 6

- (2

- (ethylthio)propyl)

- 4

- oxo

- 2

- propyl

- 4,5,6,7

- tetrahydrobenzoxazole. In contr ast, evaluati on of the data of s ethoxydim total residues shows that they remain stable at all three pHs tested.

Sethoxydim and s ethoxydim total residues degrade photolytically in both water and soil. In pH

8.7 buffered wate r, the calculated photolysis half

- life of s ethoxydim is 5.23 days, and the major transformation product is M1

- S or 2

- (1

- aminobutylidene)

- 5

- (2

- (ethylthio)

- propyl)

- cyclohex

- 1,3

- dione. In sandy loam soil irradiated with a xenon light source, the half

- life of s ethoxydim is approximately 1 hour, and th e major transformation product is M

- SO or 2

- (1

- ethoxyiminobutyl)

- 5

- (2

- (ethylsulfinyl)propyl)

- 3

- hydroxycyclohex

- 2

- enone. Sethoxydim total residues photodegrade slower than parent s ethoxydim in soil and water. Using a linear regression analysis, EFED calcu lated a half

- life of 19.8 days for the photolysis in water of s ethoxydim total
residues and a half

- life of 20 hours in soil.

U nder aerobic conditions, parent s ethoxydim transformed with short half

- lives (<1 day) both in soil and aquatic environments. It degraded with a half

- life of less than one day in sandy loam and sandy clay loam soils. The major transformation product at 2 months was M

- SO, and after 12 months the major product was CO 2 

### . Using aerobic clay loam soil:water and aerobic clay
soil:water s ystems, it was determined that, under aerobic aquatic conditions, s ethoxydim
transformed with a half

- life of <1 day. After 28 days, the major transformation products were

CO 2 

### , M

- SO, M2

- S, and M

- SO 2 

### . In contrast to parent sethoxydim, s ethoxydim total resi dues were more persistent. The obse rved half

- life was 1 month for s ethoxydim total residues in the aerobic sandy loam study, and 7 days in the aerobic sandy clay loam study. In an aerobic clay loam soil:water system, the calculated half

- life for s ethoxyd im total residues was 38.1 days, while in an aerobic clay soil:water system the half

- life was 32.9 days.

Unde r anaerobic conditions, parent s ethoxydim is even more persistent than under aerobic
conditions. It transformed with half

- lives of 11 to > 60 days under anaerobic soil conditions and
25

- 39 days in anaerobic aquatic metabolism studies. M

- SO was the major transformation product in both studies. It was observed that M2

- S, which was a major transformation product in the hydrolysis study, was on ly a minor transformation product in the anaerobic aquatic
metabolism study. S ethoxydim total residues we re more persistent than parent s ethoxydim in the

### 15

anaerobic studies . A half

- life of 91.6 days was observed in the anaerobic soil metabolism study,
whi le half

- lives of 132

- 187 days were observed in the anaerobic aquatic metabolism study.

The chemical properties and environmental fate parameters are tabulated in Table 4

.

Table 4

. Chemical Properties and Environmental Fate Parameters of Sethoxydim

Para meter Value Source

Selected Physical/Chemical Parameters

Molecular mass (molecular formula) 327 g/mol (C 15 H 23 NO 2 S ) (Calculated)

Vapor pressure (25 °C) 1 .6 x 10

- 7 torr EFED one

- liner

Aqueous solubility (20  C) 4700 mg/L EFED one

- liner

Henry’s Law Constant (25°C) 1.47 x10

- 11 atm

- m 3 /mol (Calculated)

Log o ctanol

- to

- water partition coefficient ( log K OW ) 1.65 EFED one

- liner

Persistence in Water

Hydrolysis half

- life (25  C) pH 5: 8.7 day pH 8.6 : 284 d ay pH 7: 155 day MRID 41475207

Aqueous photolysis half

- life (25  C) (pH 8.7) 5.23 day MRID 41475208

Persistence in Soil

Aerobic soil metabolism half

- life (25°C) < 1 day MRID 41475210

Aerobic aquatic metabolism half

- life (25 o C) < 1 day MRID 42165604

Anaerobic soil metabolism half

- life (25 °C) 1 1.2 day (sandy loam)

> 60 day (sandy clay loam) MRID 41475211

Anaerobic aquatic metabolism half

- life (25 °C) 2 5.4 day (sandy loam) 39.9 day (sandy clay loam) MRID 41475211

Mobility

Adsorption coefficients (K d ) (25 o C)* 0 .12, 0.78, 2.89, 5.64, 9.42 L/kg MRID 41475212

Aquatic Field Dissipation

T1⁄2 (day): 0.53 (Madera, CA), 8.1 (Chico, CA), 8.96 (Rosa, LA), 1.98 (Leland, MS) MRID 42165605

Fish Bioconcentration

BCF : 7X (edible) , 25X (nonedible) , 21X ( whole fish ) MRID 42118001
*The only batch equilibrium test with non

- sterile soils, conducted on M2

- SO 2 (the terminal degradate).



## c. Transformation Products

The following s cheme represents the relationship between parent sethoxydim (M) and its eight identified degradates. There are three groups of degradates: a group formed from the parent by oxidation of the sulfur atom (M group), the “amines” or M1 group , and the M2 group or tetrahydrobenzoxazoles. The first M1 group daughter (M1

- S) is formed by cleavage of the ethoxyimino group to an amino group, either by hydrolysis or aqueous photolysis. The first member of the M2 group (M2

- S) is then formed from M1

- S by ring closure to produce a tetrahydrobenzoxazole ring. Each of the three groups of degradates also has a sulfoxide (

- SO)

### 16

and a sulfone (

- SO2), to round out the total of eight degradates. This reaction dominates in aerobic soil metabolism and soil photolysis experiment s, especially to form the M

- SO and M

SO 2 

### degradates.

M Group M1 Group M2 Group

M  M1

- S  M2

- S   

M

- SO  M1

- SO  M2

- SO   

M

- SO 2 

###  M1

- SO 2 

###  M2

- SO 2



### The eight degradates include 2 daughter products, which are formed from the parent by a single reaction ( M1

- S and M

- SO ), 3 granddaughter products that are two reactions removed from t he parent ( M

- SO 2 

### , M1

- SO, and M2

- S ), 2 great

- granddaughters that are three reactions removed ( M1

- SO 2 

### and M2

- SO ), and one great

- great

- granddaughter that is four reactions removed (M2

- SO 2 

### ). It is important to note that M1

- SO, M2

- SO, M1

- SO 2 

### , and M2

- SO 2 

### may be formed by more than one pathway, and that the sulfur oxidation may be reversible under reducing
conditions.

Chemical names and structures of sethoxydim and its environmental transformation products are
listed in Table 5

.

### 17 Table 5 . Sethoxydi m and Its Environmental Transformation Products

Code Name/ Synonym Chemical Name Chemical Structure Study Type MRID Maximum %AR (day) Final %AR

(study length)

PARENT



### Sethoxydim 2

- [1

- (ethoxyimino)butyl]

- 5

- [2

-

(ethylthio)propyl]

- 3

- hydroxy

- 2

- cyclohexen

- 1

- one

CAS Reg. No. 74051

- 80

- 2

Formula: C 15 H 23 NO 2 S

MW: 327 g/mol

TRANSFORMATION PRODUCTS



### M2

- S 6

- (2

- (ethylthio)propyl)

- 4

- oxo

- 2

- propy l

4,5,6,7

- tetrahydrobenzoxazole

Formula: C 17 H 29 NO 3 S
MW: 281 g/mol Hydrolysis 41475207 81.5% (28 d)
@ pH 5 9.7% (28 d) @ pH 7 2.3% (28d) @ pH 8.6 81.5% (28 d)

@ pH 5 9.7% (28 d) @ pH 7 2.3% (28d) @ pH
8.6 Photodegradation on
soil 41475209 4.25% (0) 0.7% (16 hr)

Photolysis 41475208 5.7% (10 d) 5.7% (10 d)

Aerobic soil 41475210 1.6% (1 d) n.d. (12 m)

Anaerobic soil 41475211 2.6% (31 d) 2.4% (61 d)

Anaerobic soil 41475211 6.1% (31 d) 4.6% (61 d)



### M1

- S 2

- (1

- aminobutylidene)

- 5

- (2

- (ethylthio)

-

propyl)

- cyclohex

- 1,3

- dione

Formula: C 1 5 H 2 5 NO 2 S
MW: 283 g/mol Photodegradation on
soil 41475209 3.2% (0) 0.8% (16 hr)

Photolysis 41475208 29.1% (10 d) 29.1% (10 d)

Aerobic soil 41475210 4.1% (1 d) n.d. (12 m)

Anaerobic soil 41475211 3.7% (0) 1.6% (61 d)

Anaerobic soil 41475211 21.6% (61 d) 21.6% (61 d)

### 18 Code Name/ Synonym Chemical Name Chemical Structure Study Type MRID Maximum %AR (day) Final %AR

(study length)

M

- SO 2

- (1

- ethoxyiminobutyl)

- 5

- (2

-

(ethylsulfinyl)propyl)

- 3

- hydroxycyclohex

2

- enone

Formula: C 17 H 29 NO 4 S
MW: 343 g/mol Hydrolysis 41475207 1.3% (1 d) @ pH 5 0.9% (28 d) @ pH 7 1.3% (28d) @ pH 8.6 0.5% (28 d)

@ pH 5 0.9 % (28 d) @ pH 7 1.3% (28d) @ pH
8.6 Photodegradation on

soil 41475209 58.8% (4 hr) 43% (16 hr)

Photolysis 41475208 2% (4 d) 0.8% (10 d)

Aerobic soil 41475210 70.8% (2 d) 0.5% (12 m )

Anaerobic soil 41475211 60.3% (31 d) 51.5% (61 d)

Anaerobic Aquatic 41475211 47.2% (61 d) 47.2% (61 d)



### M

- SO 2 2

- (1

- ethoxyiminobutyl)

- 5(2

-

(ethylsulfonyl)propyl)

- 3

- hydroxycyclohex

2

- enone

Formula: C 17 H 29 NO 5 S
MW: 359 g/mol Aerobic soil 41475210 11.2% (7 d) 0.4% (12 m)

Anaerobic soil 41475211 14% (61 d) 14% (61 d)

Anaerobic Aquatic 41475211 7.1% (61) 7.1% (61 d)



### M1

- SO 2

- (1

- aminobutylidene)

- 5

- (2

- (ethylsulfinyl )

-

propyl)

- cyclohex

- 1,3

- dione

Formula: C 1 5 H 2 5 NO 3 S
MW: 299 g/mol Photodegradation on
soil 41475209 3.6% (16 hr) 3.6% (16 hr)

Photolysis 41475208 4.8% (10 d) 4.8% (10 d)

Aerobic soil 41475210 2.8% (1 d) 0.4% (12 m)

Anaerobic soil 41475211 1.9% (61 d) 1.9% (61 d)

Anaerobic aquatic 41475211 4.1% (61 d) 4.1% (61 d)

### 19 Code Name/ Synonym Chemical Name Chemical Structure Study Type MRID Maximum %AR (day) Final %AR

(study length)

M1

- SO 2 2

- (1

- aminobutylidene)

- 5

- (2

- (ethyltho)

-

propyl)

- cyclohex

- 1,3

- dione

Formula: C 1 5 H 25 NO 3 S
MW: 315 g/mol Aerobic soil 41475210 4.0% (1 d) 0.8% (12 m)

Photolysis 41475208 1.9% (10 d) 1.9% (10 d)

Anaerobic soil 41475211 1.4% (61 d) 1.4% (61 d)

Anaerobic aquatic 41475211 2.7% (61 d) 2.7% (61 d)



### M2

- SO 6

- [2

- (Ethylsulfinyl)propyl]

- 4

- oxo

- propyl

4,5,6,7

- tetrahydrobenzoxazole

Formula: C 15 H 2 3 NO 3 S
MW: 297 g/mol Hydrolysis 41475207 2.0% (28 d) @ pH 5 0.9% (28 d) @ pH 7 0.1% (28d) @ pH 8.6 2.0% (28 d)

@ pH 5 0.9 % (28 d) @ pH 7 0.1% (28d) @ pH
8.6 Photodegradation on
soil 41475209 2.6% (16 hr) 2.6% (16 hr)

Photolysis 41475208 1.5% (10 d) 1.5% (10 d)

Aerobic soil 41475210 9.9% (1 d) 1.2% (12 m)

Anaerobic soil 41475211 2.8% (31 d) 0 (61 d)

Anaerobic aquatic 41475211 3.4% (31d) 1.2% (61d)



### M2

- SO 2 6

- [2

- (Ethylsulfonyl)propyl]

- 4

- oxo

- propyl

4,5,6,7

- tetrahydrobenzoxazole

Formula: C 1 5 H 2 3 NO 4 S
MW: 313 g/mol Aerobic soil 41475210 15.2% (3 m) 9.0% (12 m)

Anaerobic soil 41475211 4.3% (61 d) 4.3% (61 d)

Anaerobic aquatic 41475211 1.7% (61 d) 1.75 (61 d)



### Carbon dioxide Carbon dioxide

Formula: CO 2 MW: 44 g/mol Aerobic soil 41475210 48.4% (12 m) 48.4% (12 m)

### 20



## 6. Receptors

T he t oxicity endpoints that will be used in risk assessment for aquatic and terrestrial organisms exposed to sethoxydim are presented in Table 6 and Table 7 below. A complete list of the ecotoxicity data available for sethoxydim can be found in Appendix A

.

Sethoxydim TGAI is slightly to practically non

- toxic to fr eshwater and estuarine/marine fish and
invertebrates on an acute exposure basis

. S ethoxydim as the end

- use products (EP) are highly to moderately toxic to freshwater and estuarine/marine fish and invertebrates on an acute exposure
basis

. Thus suggesting that the end

- use product (EP) is more sensitive than the TGAI to aquatic taxa on an acute exposure basis. The RED attributed the increase in toxicity to the presence of solvent materials in the EP, and not the active ingredient, sethoxydim. Reductions in post

- hatch survival, standard length, and wet weight, were noted effects resulting from chronic exposure of sethoxydim to freshwater fish, and reductions in survival and length were noted effects noted effects resulting from chronic exposure of sethoxydim to estuarine/marine invertebrates. There were no effects that were noted from chronic exposure of sethoxydim to estuarine/marine fish. No freshwater invertebrate toxicity data is available for sethoxydim, only mysid chronic toxicity
data is available. I t should be noted, that only one chronic study, a fathead minnow study, is available for the TGAI, all other available chronic toxicity data that is available uses an E P, and not necessarily the same EP for the different studies. For aquatic plants, e ffects were observed in the aquatic vascular plant toxicity study with reed mannagrass ( Glyceria maxima )

, but n o effects were observed in the aquatic no n

- vascular plant toxicity studies

.

Sethoxydim is practically non

- toxic to birds and mammals on an acute exposure basis. Toxicity to terrestrial invertebrates has only been assessed for adult honey bees via an acute contact

exposure , and sethoxydim is classified as practically non

- toxic to adult honey bees

. There were
no mortalities that were t reatment related in any of the acute or subacute bird studies. M ortality
and numerous clinical signs of toxicity were noted in the acute mammalian studies for both the active ingredient and EP. Reduction in the proportion of the number of hatchlings to live 3

- week (21

- d) viable embryos were the most sensitive endpoints in the new mallard duck reproduction study, and there were no effects observed in the bobwhite quail reproduction study.
The mammalian 2

- generation reproduction st udy indicated effects to mammals based on effects to the offspring including tail abnormalities in F 1 

### a and F 1 

### b offspring; malformations described as threadlike tail, no anal opening, malformed hindlimb, malpositioned kidneys, cleft lip, c left palate, and m icropht h almia. However, no systemic effects to parent animals or r eproductive
effects were observed , and n o dose

- related gross or microscopic lesions, or developmental variations (cannibalism complicated the evaluation) were observed

.

For terrestrial d icotyledonous plant species, t here were no responses that were ≥25% for plants exposed to sethoxydim at the treatment rates tested ( i.e., 0.47 lbs a.i./A (seedling emergence,

MRID 44204801 ) or 0.5 lbs a.i./A (v egetative vigor, MRID 41885906 ) )

. However, the available Tier II vegetative vigor study was conducted with technical grade test material and not a typical
end

- use product (TEP) as described in the CFR, and Agency test guidelines. Additional data is needed for dicot plants. For terrestrial monocoty ledonous plant species, the most sensitive species was ryegrass ( Lolium perenne ) in all tests conducted

. The most sensitive parameter was

### 21

phytotoxicity and dry weight in the seedling emergence study (MRID 43614603) and dry weight in the vegetative vigor study (MRID 47691704)

.



## a. Effects to Aquatic Organisms

Table 6

. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for Sethoxydim Aquatic Animals

Species Test

Substance (% a.i.) Acute Toxicity Chronic Toxicity

96

- hr LC 50 /EC 50 (95% CI) (mg a.i./L) (Toxicity Classification) 48

- hr EC 50

(95% CI) (mg a.i./L) (Toxicity Classification) MRID

(Study Classification) NOAEC/

LOAEC (mg a.i./L) (Endpoints) MRID

(Study Classification)

Rainbow trout ( Oncorhynchus mykiss ) TGAI

97.3% 170 (142

- 204)

(nominal) (practically non

toxic) 1 -- 00042815 (Acceptable) ND ND

EP
19.3% 1.2 (1.0

- 1.7)

(measured) (moderately toxic) 2 -- 41885902 (Acceptable) ND ND

Fathead
minnow ( Pimephales promelas ) TGAI

94.8% -- -- ND 4.86/9.59 (post

- hatch
survival &
standard length) 3 47691702

(Acceptable)

EP
19.6% 1.58 (1.2

- 2.08)

(measured) (moderately toxic) 4 -- 47691701 (Acceptable) 0.230/0.474

(standard length, wet weight &
post

- hatch survival) 5 47691703

(Acceptable)

Sheepshead
Minnow ( Cyprinodon variegates ) TGAI

97.8% >145.8

(measured) (practically non

toxic) -- 42315101 (Acceptable) ND ND

EP
18% (Acute),
40.7% (Chronic) 3.5 (2.7

- 4.5)

(nominal) (moderately toxic) 6 -- 41510602 (Acceptable) 98/>98

(no effects) 7 43614601

(Supplemental)

Waterflea ( Daphnia

magna ) TGAI

97.3% -- 78.1 (nominal) (slightly toxic) 8 00042816

(Acceptable) ND ND

EP
19.3% -- 2.6 (2.0

- 3.3) (measured) (moderately toxic) 9 41885903

(Acceptable) ND ND

Eastern oyster ( Crassostrea virginica ) TGAI

94.5% -- >109 (measured) (practically

non

- toxic) 42537401

(Acceptable) -- --

EP
20.4% -- 0.9 (0.6

- 1.0) (nominal) (highly toxic) 10 41607207

(Acceptable) ND ND

### 22 Aquatic Animals

Species Test

Substance (% a.i.) Acute Toxicity Chronic Toxicity

96

- hr LC 50 /EC 50 (95% CI) (mg a.i./L) (Toxicity Classification) 48

- hr EC 50

(95% CI) (mg a.i./L) (Toxicity Classification) MRID

(Study Classification) NOAEC/

LOAEC (mg a.i./L) (Endpoints) MRID

(Study Classification)

Mysid ( Americamysis
bahia ) TGAI

97.8% >141.8

(measured) (practically non

toxic) -- 42315102 (Acceptable) ND ND

EP
18% (Acute),
43.1% (Chronic) 0.8 (0.7

- 1.1)

(nominal) (highly toxic) 10 -- 41510604 (Acceptable) 6.5/13

(survival & Length) 43614602

(Supplemental) 11

Aquatic Plants

Species Test

Substance Endpoint

(mg a.i./L) Effect (MRID; Study Classification)

Vascular Plants

Reed Mannagrass ( Glyceria

maxima ) EP

19.3% 21

- day EC 50 = 0.21

21

- d NOAEC = 0.093 Growth rate based on total leaf length (48000902, Acceptable) 12

Non

- Vascular Plants

Marine Diatom ( Skeletonema

costatum ) TGAI

99.8% 120 hr EC 50 > 0.250

NOAEC = 0.250 No effects ( 43626101; Acceptable )

EP = End

- Use Product; ND = No data;

-- = not applicable

1 Behaviors/sublethal effects noted included being irritated, erratic swimming, dark discolored pigment, and labored respiratio n.

2 Effects included mortality, dark discoloration, surfacing, fish on bottom of test chamber, vertical orientation, flared gills, loss of equilibrium, quiescence, and/or labored respiration observed in all test concentrations.

3 Post hatch survival and standard length were significantly re duced in the highest test concentration compared to the negative
control.

4 In the highest test concentration (10.6 mg a.i./L) 100% mortality was observed. Observed sublethal effects included: loss of equilibrium, discoloration, surfacing and lying on the bottom of the test chamber. Poast® (BAS 562 05 H) was the formulation that
was tested.

5 Poast® (BAS 562 05 H) was the formulation that was tested. The most sensitive endpoints were standard length and wet weight; additionally post

- hatch survival was also reduced in the highest treatment level as only one juvenile fish survived to test termination.

6 There was 100% mortality observed in the test concentrations > 4.5 mg/L. Observed sublethal effects included loss of equilib rium and change in behavior (su rfacing) during the test.

7 A formulated product Poast 3.5EC (Reg. # 7679

- 129) was used; the study was supplemental as a LOAEC was not determined in this study.

8 Dose response slope is 4.73725.

9 There was 100% immobility observed in the two highest test concentrations, 4.6 and 8.9 mg/L after 4 hours. Observed sublethal effects included daphnids being observed on the bottom of the tank.

10 There was 100% mortality observed in the test concentrati ons ≥ 1.1 mg/L, and no sublethal effects were observed in any test

concentration.

1 1 Erratic swimming and/or lethargy were noted in the two highest test concentrations (56 and 113 mg a.i./L) until complete mortality occurred on days 4 and 14 for each gro up, respectively. Other endpoints affected included reproduction (neonates produced), and weight (dry and wet). The study was classified as supplemental because it was conducted with an end

- use product (EP) and not technical grade (TGAI) test material as required by CFR 158.490.

12 The endpoints were based on 21

- day results, in addition to the most sensitive endpoint of total leaf length, growth rate based on dry weight also showed effects, and the resulting EC50 and NOAEC values were 2.9 and 0.093 mg a.i ./L, respectively. The percent

### 23

growth inhibition of total leaf length in treated culture as compared to the control ranged from 10 to 95%. Rhizome developm ent was affected and plants showed moderate to strong necrotic symptoms.



## b. Effects to Terrestrial O rganisms

Table 7

. Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for Sethoxydim

Terrestrial Animals

Species/

Test substance (% a.i.) Acute Toxicity Chronic Toxicity

48

- hr LD 50 (μg a.i./bee) 14

- day LD 50

(95% CI) (mg/kg

- bw) (Toxicity Classification) 8

- day LC 50

(mg a.i./kg

diet (ppm)) (Toxicity Classification) MRID

(Study Classification) NOAEC/LOAEC

(mg a.i./kg

- diet (ppm)) (Endpoints) MRID

(Study Classification)

Bobwhite Quail ( Colinus virginianus )/ (TGAI; 97.3%,
Acute & 96.8% Chronic) -- ND >5620 1 (practically

non

- toxic) 00042814

(Acceptable) 1000/≥1000

(no effects) 44003401

(Acceptable)

Mallard Duck ( Anas platyrhynchos )/ (TGAI; 97.3%, Acute; 94.8 & 96.8% Chronic) -- > 2510 2 (practically

non

- toxic) >5620 1

(practically

non

- toxic) 00042813

(Acceptable)
&
00072862 (Acceptable) 466/953

(proportion of
number of hatchlings to live
3

- week (21

- d) viable embryos) 3 48000901

(Acceptable)

Laboratory rat ( Rat t us norvegicus )/ (TGAI; 94

- 99%) -- 2676 (F); 3125 (M) 4 (practically

non

- toxic; Toxicity Category III) -- 00045847 (Acceptable) 600/3000 5

(Offspring, developmental: tail
abnormalities in F 1 a and F 1 b offspring;
malformations
described as threadlike tail, no anal opening, malformed hindlimb, malpositioned kidneys, cleft lip, cleft palate, and micropht h almia. No systemic or reproductive effects were observed.) 41510606

&
43366401 (Acceptable)

Laboratory rat (EP, 18%) -- 4385 (F); 5000 (M) (practically non

toxic; Toxicity Category III) 6 -- 00046326 (Acceptable) ND ND

Laboratory rat (TGAI; 94

- 99%) -- Inhalation LC 50 = 6.03 mg/L (Males) (Toxicity category III) 7 00045849 (Acceptable) -- --
Honey Bee ( Apis mellifera )/ (TGAI; 98.9%; acute contact) 10

( moderately

t oxic) 8 -- -- 41510607 (Acceptable) -- --

### 24 Terrestrial Animals

Species/

Test substance (% a.i.) Acute Toxicity Chronic Toxicity

48

- hr LD 50 (μg a.i./bee) 14

- day LD 50

(95% CI) (mg/kg

- bw) (Toxicity Classification) 8

- day LC 50

(mg a.i./kg

diet (ppm)) (Toxicity Classification) MRID

(Study Classification) NOAEC/LOAEC

(mg a.i./kg

- diet (ppm)) (Endpoints) MRID

(Study Classification)

Terrestrial Plants Species /

Test substance (% a.i.) Seedling Emergence Vegetative Vigor

MRID Study
Classification EC 25 (lb a.i./acre) NOAEC

(lb a.i./acre) EC 25

(lb a.i./acre) NOAEC

(lb a.i./acre)
Monocot: Ryegrass ( Lolium perenne ) (EP, 50.5%, SE; & 19.6%, VV) 0.078 0.059 (phytotoxicity, dry weight) 9 0.0086 0.00276 (dry weight) 1 0 43614603 (SE)

& 47691704 (VV) Supplemental
& Supplemental

Dicots:
All Dicots (EP, 50.5%, SE; & TGAI, 95.4%, VV) -- 0.47 (no effects) 11 -- 0.5 (no effects) 1 2 44204801 (SE)

& 41885906 (VV) Supplemental

& Supplemental

EP = End

- Use Product; ND = No data;

-- = not applicable

1 5 days of exposure via the diet, followed by 3 days of observation of chemical free diet

. 2 No mortality, or behavioral abnormalities at test concentrations tested; however, there was a reduction in feed consumption at the 1000 and 1590 mg a.i./kg

- bw dose levels.

3 No treatment related mortalities were observed, although one (1) mortality was observed in the 500 ppm a.i. dose level withou t prior clinical signs of toxicity.

4 Signs of toxicity observed included: ataxia, sedation, hypotonia, lacrymation, salivation, t remor, paralysis, fall of body temperature,
and urine incontinence diarrhea.

5 NOAEC/LOAEC = 30/150 mg/kg

- bw /day

. No dose

- related gross or microscopic lesions, or developmental variations (cannibalism complicated the evaluation). No parental toxicity was observed at either the mid or high

- dose, and there were problems with the feed formulation stability, homogeneity, and dose concentration that made it impossible to ascertain the actual doses used. Howeve r, additional information was submitted by the regis trant, and the highest dose used in the reproduction study was 3000 ppm administered in the diet, or approx. 150 mg/kg/day. This is about one

- fourth the gavage LEL of 650 mg/kg/day in a rat developmental toxicity study (Project No. 92

- 3826)

– a maternally toxic dose that had not effect on reproduction. Taking the differences in dosing regimens and durations, HED presented in their September 1994 memo that the 3000 ppm dose was defined as a free

- standing NOEL, and the reproduction study was upgraded to CORE

- minimum.

6 Signs of toxicity observed included: Dyspnea, apathy, spastic gait, and poor general state were symptoms in all dosage groups

. Abnormal position, staggering, piloerection, and salivation were observed in the four (4) highest dosage groups; at onia, pain reflex absent, narcotic like state, and exciccosis were present in the three (3) highest dosage groups. At necropsy, dead animals s howed heard dilatation, acute congestive hyperemia with atonic, diarrheaic intestine; and sacrificed animals show ed several cases of adhesions of forestomach to liver, spleen, peritoneum with thickened forestomach and focal thickenings.

7 The exp osure was 4 hours in duration; n o mortalities occurred in an y treatment or control groups. Lacrymation and salivation were observed at 2 hours, lasting to 4 hours after inhalation exposure in both experimental and vehicle control groups. Body weigh ts in all groups decreased at 4 hours, but recovered afterwards, with stunted rec overy in experimental animals, and n o other t oxic effects were
observed.

8 Mortality was reported at 24 hours, and not 48 hours. No mortalities were observed for the technical material or acetone con trol

groups in the acute contact (topical application) test. Information for other two additional exposure routes bees were exposed to is
available in this study

, they are spray and oral exposure routes . The study reported a total of 10% mortality from spray, and 5% mortality was observed from oral exposure, both at 24 hours

. 9 Tier II seed germinati on and seedling emergence study; ryegrass wa s the most sensitive monocot species tested . Dicot species were not tested in this study, only a Tier I study was completed as discussed.

10 Tier I I vegetative vigor study using EP, ryegrass wa s the most sensitiv e monocot species tested . Dicot species were not tested in this Tier II study with the EP, however, the test material used in the other Tier II vegetative vigor study was TGAI, which is not in accordance with Agency test guidelines.

### 25

11 Tier I seed germination and seedling emergence study; no effects for all dicots, except, there was a 15% response for phytotoxicity for cabbage, which was the only dicot plant species to show any response.

12 Tier II vegetative vigor study using TGAI, no effects wer e observed in dicot species; however, since the test material was TGAI and

not EP, which is not in accordance with Agency test guidelines, the study was classified as supplemental.



## c. Ecological Incidents

The ecological incident information system (EIIS) is an OPP database that houses ecological
incidents that ha ve been reported to the Agency. When available, EIIS includes date and location of an incident, type and magnitude of effects observed in various species, use(s) of pesticides known or suspected of contributing to the incident, and results of any chemical residue analysis or other analyses conducted during incident investigation. EIIS incidents are categorized according to the certainty that the incident resulted from pest icide exposure. The Avian

M onitoring System (AIMS) is a database administered by the American Bird Conservancy that contains publicly available data on reported avian i ncidents involving pesticides. Many of the
incidents listed in this database are also in the EIIS. The Aggregate I ncident Reports database is an Agency database that may contain minor wildlife and plant incidents for chemicals.

Reviews of the Ecological Incident Information System (EIIS, version 2.1 .1 ), the Avian Incident Monitoring System (AIMS) 1 

### , and the EPA Incide nt Data System (IDS , Aggregate Incident Reports database ) were conducted on January 23, 2015. T here were four ecolog ical incidents reported in EIIS (I000232

- 001, I011716

- 002, I018428

- 016, and I021485

- 016)

, summarized in Appendix B

. Two incidents ( I000232

- 001 and I011716

- 002 ) involved fish, and two incidents ( I021485

- 016 and I018428

- 016 ) involved terrestrial plants. Of the two incidents that involved fish, one was identified to be from an accidental misuse of the pesticide ( I011716

- 002 ), while the other incident ( I000232

- 001 ) was identified to be from a registered use. Both incidents however, occurred in the presence of other chemicals that were identified to be the probable cause of the incident due to greater toxicity; however sethoxydim was also applied at the same time and was therefore listed as a possible cause of each incident. The two incidents on terrestrial plants, also involved a registered use ( I021485

- 016 ), as well as an identified intentional misuse ( I018428

- 016 ). The identified regi stered use incident on terrestrial plants ( I021485

- 016 ), occurred in the presence of additional pesticides, and sethoxydim is listed as a possible cause of the incident. The identified intentional misuse ( I018428

- 016 ) on terrestrial plants indicated that s ethoxydim was applied at twice the labeled rate, which could have caused the observed damage to the watermelon fruit and foliage, but no pesticide residues were detected on the fruit, and sethoxydim was listed as a possible cause of the incident.

There were no reported incidents in the AIMS database for sethoxydim

. T here were a total of 7
minor incidents in the Aggregate Incident R eports database for sethoxydim . Two minor plant incidents were reported in 2000 (010790

- 00010) for the POAST formulation of sethoxydim; three minor plant incidents were reported in 2001 (012391

- 00017) for the POAST Plus formulation of sethoxydim; one minor plant incident was reported in 2002 (013679

- 00004) for the BASF POAST formulation of sethoxydim; and one minor wildlife in cident was reported in 2004 (014757

- 00010) for the POAST Plus formulation of sethoxydim

. T he lack of reported incidences should not be construed as the absence of incidents. Incident reports for non

- target organisms typically provide information only on mortality events and plant damage. Sublethal

1 http://www.abcbirds.org/abcprograms/policy/pesticides/aims/aims/index.cfm

### 26

effects in organisms such as abnormal behavior, reduced growth and/or impaired reproduction are rarely reported, except for phytotoxic effects in terrestrial plants.



## 7. Exposure Pathways of Concern

The environm ental fate properties and use patterns of sethoxydim indicate that direct spray, spray drift, and runoff represent potential transport mechanisms to aqu atic and terrestrial organisms. The conceptual model will consider sethoxydim and its eight degradates a s the
residue of concern.

Drinking water and inhalation exposure pathways were screened using the SIP (Screening Imbibition Program, version 1.0) and STIR (Screening Tool for Inhalation Risk, version 1.0) screening methods. Drinking water exposure alone was determined be a potential pathway of concern for mammalian species on an acute basis, and mammalian and avian species on a
chronic basis ( Table s 8 and 9 ). Inhalation pathway was determined to be a potential exposure pathway of low conce rn (no LOC exceedances were found for STIR). O utputs for each model
are located in Appendix C . SIP and STIR are described in detail at: http://www.epa.gov/oppefed1/models/terrestria l/index.htm

.

Table 8 . SIP Mammalian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 808 808 Adjusted toxicity value (mg/kg

- bw) 2058 23 Ratio of exposure to toxicity 0.393 35

Conclusion* Exposure through drinking water alone is a potential concern for

mammals Exposure through drinking

water alone is a potential
concern for mammals



### Table 9 . SIP Avian Results

Parameter Acute Chronic Upper bound exposure (mg/kg

- bw) 3807 3807 Adjusted toxicity value (mg/kg

- bw) 198290 23 Ratio of exposure to acute toxicity 0.019 165

Conclusion* Drinking water exposure alone is NOT a potential
concern for birds Exposure through drinking water alone is a potential
concern for birds
*Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. Therefore, when aggregated with other routes ( i.e ., diet, inhalation, dermal), pesticide exposure through drinking water may contribute to a total exposure that has potential for effects to non

- target animals.



## 8. An alysis Plan

The most recent ecological risk assessment wa s for an IR

- 4 petition (D418333, December 2014 ).
The action wa s for expansion to new crop groupings and in conjunction with the same application rates of the proposed uses, the past risk assessments ( D313456, D314420

, D 312568, and D312561), which includes the 2005 RED ( D 312568, D 312561 ), will be relied upon because they adequately describe potential risks from the new proposed uses. The conclusions from the

### 27

past assessments including the recently proposed uses (as the latest risk assessment was just conducted in December 2014). The assessments concluded that sethoxydim do not result in LOC exceedances for aqu atic animals or aquatic plants . Both TGAI endpoints corresponding run off EECs and spray drift EECs with the TEP endpoints were analyzed separately

. Risks exceeding the LOC were identified for mammals and terrestrial monocot plants

. There are
chronic dos e

- based LOC exceedances for multiple size classes of mammals consuming a variety of dietary items, and e xceedances occur even with a single application of sethoxydim. Risk exceeding the LOC may affect l isted monocot grass species at >1000 feet and non

- lis ted monocot grass species at up to 509 feet from field s treated with sethoxydim

. R isks to bees are

un certain in the absence of data; therefore, EFED recommends that additional data be requested to allow for a more comprehensive evaluation of potential effects to honey bees. EFED will evaluate those data when they are submitted and will work with PRD to address any risks of concern identified by those data. In addition to the need for honeybee data, there is the need for
data to evaluate the terminal de gradate, sulfone

.



## a. Stressors of Concern

i. Ecological Risk Assessment

For the sethoxydim ecological risk assessment, the stressors of concern in this assessment are the parent compound sethoxydim and its eight degradates. The eight degradates are grouped into three sets. These are (1) the sulfoxide (M

- SO) and sulfone (M

- SO2) of the parent chemical, (2) the hydrolysis product M1

- S, its sulfoxide (M1

- SO), and sulfone (M1

- SO2), and (3) the hydrolysis/ring closure product (M2

- S), and its sulfoxide (M2

- SO) and sulfone (M2

- SO2 ).

ii. Drinking Water

Sethoxydim and its eight degradates are the residue s of concern for the sethoxydim drinking water exposure assessment in support of human health dietary risk assessment

. The results of the

recent 2014 drinking water exposure assessment (DP 4 18281 ) will be used for registration review unless an update is warranted due to new data or assessment methodologies.



## b. Measures of Exposure

Past assessments of sethoxydim EFED have use d standard available models to evaluate potential exposures to aquatic and terrestrial organisms as described at http://www.epa.gov/oppefed1/models/water/index.htm and http://www.epa.gov/pesticides/science/models_db.htm

. T he Surface Water Concentration Calculator (SWCC) is currently the model that is typically use d to estimate aquatic exposure. T

REX, Bee

- REX, and TerrPlant are currently the models that are typically used to estimate terrestrial exposure.

i. Available Monitoring Data

Sethoxydim is not an analyte in any of the following water monitoring programs: the California Department of Pesti cide Regulation ( CDPR) surface water database

- http://www.cdpr.ca.gov/docs/emon/surfwtr/surfcont.htm , the USGS NAWQA surface and

### 28

ground water database

- http://cida.usgs.gov/nawqa_queries_public/ , and the USEPA STORET
Data Warehouse

- http://www.epa.gov/storet/

. Monitoring will be considered in the assessment
to the extent that any future data on sethoxydim are available.



## c. Measures of Effect

Toxicity data presented in Section 6 of this pro blem formulation would be used to calculate risk quotients. Any additional information submitted by the registrant or found in the open literature prior to con duct of the risk assessment would also be considered. The open literature studies are
identified using EPA’s ECOTOXicology database ( ECOTOX) (USEPA, 2007 a ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The evaluation of both sources of data can also provide insight int o the direct and indirect effects of pesticides on biotic communities from loss of species that are sensitive to the chemicals and from changes in structure and functional characteristics of the affected
communities.



## d. Endangered Species Assessments

Consistent with the Agency’s responsibility under the Endangered Sp ecies Act (ESA), the Agency would evaluate risks to federally listed

, threatened and/or endangered (listed) species from registered uses of pesticides in registration review

. The process for evaluating potential risks to listed species is further described at http://www.epa.gov/oppfead1/endanger/litstatus/riskasses.htm

.



## e. Endocrine Disruptor Screening P rogram

Sethoxydim was not included in the first group of 67 chemicals issued an orde r to conduct Tier 1 EDSP testing and is not on the second list of chemicals for Tier 1 screening

. For additional
information the EDSP program, visit http://www.epa.gov/endo/

.



## 9. Preliminary Identification of Data Gaps

a. Environmental Fate

Table 10 identifies environmental fate studies by MRID that offer data for each guideline requirement, as well as study classifications and whether or not further data are needed in order to support risk assessment.

Table 10 . Submitted Environmental Fate Data for Sethoxydi m

OCSPP
Guideline Data Requirement Submitted
Studies (MRID) Study

Classifications Sufficient

for risk
assessment? Current Additional Data Need

835.2120 Hydrolysis 41475207 Acceptable Yes None

835.2240 Aqueous photolysis 41475208 Acceptable Yes None

835.2410 Soil photolysis 4147520 9 Acceptable Yes None

### 29

OCSPP
Guideline Data Requirement Submitted
Studies (MRID) Study

Classifications Sufficient

for risk
assessment? Current Additional Data Need

835.4100 Aerobic soil

metabolism 41475210 Acceptable Yes None

835.4200 Anaerobic soil

metabolism 41475211 Acceptable Yes None

835.4400 Anaerobic aquatic

metabolism 42165603

42165604 Acceptable Yes None

835.1230
835.1240 Adsorption/

desorption and leaching 41475212 Acceptable Yes None

835.6100 Terrestrial field

dissipation 41510608

4151060 9
41510610
41510611

44311001
44352401 Supplemental Yes T otal sethoxydim residues were analyzed, rather than the parent compound and its eight degradates. Since the total toxic residues approach will be used, so need to repeat the study

.

835.6200 Aquatic field

dissipation 42165605 Acceptable Yes None

850.1730 Fish

bioconcentration 42118001 Acceptable Yes None



## b. Effects

Table 1 1 and
Table 1 2 identif

y ecological effects studies by MRID that offer data for each gu ideline requirement, as well as study classifications and whether further data are needed in order to support risk assessment. The rationale for additional non

- guideline data requested is presented
below the tables.

Table 11

. Submitted Aquatic Ecological Effects Data for Sethoxydim

OCSPP
Guideline Data Requirement Submitted
Studies (MRID) Study

Classifications Sufficient

for risk
assessment? Current Additional Data

Need

850.1010 Freshwater

invertebrate acute toxicity 00042816 Acceptable

Yes None ; however, additional information regarding the TGAI study (MRID 00042816 ) could alleviate some uncertainty as only nominal concentrations were reported. However, the sethoxydim formulation s are more toxic than the active ingredient alone. 41885903 Acceptable

850.1025
850.1035
850.1045
850.1055 Saltwater

invertebrate acute toxicity 42537401 Acceptable

Yes None . Although the TGAI studies ( 42537401 & 42315102 ) reported mean

- measured concentrations, the sethoxydim
formulation s are more toxic than the active ingredient alone. 41607207 Acceptable

42315102 Acceptable

41510604 Acceptable

### 30

OCSPP
Guideline Data Requirement Submitted
Studies (MRID) Study

Classifications Sufficient

for risk
assessment? Current Additional Data

Need

850.1075 Freshwater fish acute

toxicity 00042815 Acceptable

Yes No ne; however, again only
nominal concentrations were reported in the TGAI studies (MRID’s 0004281 5, and

00072863 ), additional
information or new studies measuring the test
concentrations could alleviate some uncertainty. However, the sethoxydim formulation s are more toxic than the active ingredient alone. 41885902 Acceptable

00072863 Acceptable

41885901 Acceptable

47691701 Acceptable

850.1075 Saltwater fish acute

toxicity 42315101 Acceptable

Yes Although the TGAI study ( 42315101 ) reported measured concentrations, the sethoxydim
formulation is more toxic than the active ingredient alone. 41510602 Acceptable

850.1300 Freshwater

invertebrate life cycle (None) (Not applicable) No Only chronic estuarine/marine invertebrate toxicity data is available, and chronic freshwater invertebrate toxicity data is required by CFR
158.630 . The study should be
conducted with the TGAI.

850.1350 Saltwater

invertebrates life cycle 43614602 Supplemental No The study was classified as supplemental because it was
conducted with an end

- use product (EP) and not technical grade (TGAI) test material as required by CFR 158. 630. A study should be conducted
with the TGAI.

850.1400 Freshwater fish

early

- life stage 47691702 Acceptable Yes None. S tudy were conducted
with both the TGAI and EP. 47691703 Acceptable

850.1400 Saltwater fish

early

- life stage 43614601 Supplemental No The study was supplemental as
a LOAEC was not determined
in this study. In addition, the study was conducted with an
end

- use product (EP) and not technical grade (TGAI) test material as required by CFR

158. 630. A study should be
conducted with the TGAI.

850.1500 Fish life cycle (None) (Not applicable) Yes None

850.4400 Aquatic plant

Toxicity Test using

Lemna spp. 43614605 Supplemental Yes None; an acceptable aquatic vascular plant study for a grass species was completed using Glyceria maxima as the test species. This was deemed to be an acceptable alternative.

### 31

OCSPP
Guideline Data Requirement Submitted
Studies (MRID) Study

Classifications Sufficient

for risk
assessment? Current Additional Data

Need

NG Aquatic vascular

plant Toxicity Test using Glyceria

maxima 48000902 Acceptable Yes None; an acceptable aquatic vascular plant study for a grass species was completed using Glyceria maxima as the test species. This was deemed to be an acceptable altern ative.

850.4500 Algal toxicity 43626101 Acceptable Yes Marine diatom; Skeletonema

costatum

. N o effects were
observed in the study

.

43614607 Acceptable Yes Freshwater green alga; Selenastrum capricornutum

. No
effects were observed in the study.

43614606 Acceptable Yes Freshwater diatom; Navicula pelliculosa

. No effects were observed in the study.

850.4550 Cyanobacteria 43614608 Acceptable Yes Freshwater blue

- green alga; Anabaena flos

- aquae

. No effects were observed in the study.



### Table 12

. Submitted Terrestrial Ecological Effects Data for Sethoxydim

OCSPP
Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Sufficient

for risk
assessment? Current Additional Data Need

850.2100 Avian oral

toxicity 00042813 Acceptable No Yes

– a passerine species is needed to fulfill guideline requirements. Tier 1 EECs from past assessments ranged from approximately 19

- 3 12 mg/kg, and the acute LD50 was

>2 51 0 mg/kg

- bw and the sub

- acute LC50 was >5620 mg/kg

- diet. The passerine LC50 would have to be at
least 0.53 times (3000/ > 5620) lower than the other avian species to result in an acute listed species LOC
exceedance of 0.1. B ased on this,

t here is little margin of safety given
the lack of acute effects to other
bi rds

, but additional data would likely add to the risk assessment

.

850.2200 Avian dietary

toxicity 00042814 Acceptable Yes None

00072862 Acceptable

850.2300 Avian

reproduction 44003401 Acceptable

Yes None

44003402 Supplemental

48000901 Acceptable

### 32

OCSPP
Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Sufficient

for risk
assessment? Current Additional Data Need

870.1100 Mammalian

acute oral 00045847 Acceptable
Yes None

00046326 Acceptable

870.1300 Mammalian

acute inhalation 00045849 Acceptable Yes None

870. 3800 Mammalian 2

-

generation Reproduction 41510606

&

43366401 Acceptable Yes None

850.3020 Honey bee adult

acute contact toxicity 41510607 Acceptable Yes Mortality was reported at 24 hours,
and not 48 hours. No mortalities
were observed for the technical

material or acetone control in the acute contact (topical application)
test method

.

Special study

, OECD 213 Honey bee adult

acute oral toxicity (None) (Not applicable) No An acute oral toxicity study with the adult honey bee is still needed.

I nformation for other exposure routes for adult honey bees (oral included) was presented in MRID
41510607. M ortality was observed via the oral exposure route at 24
hours ; however, this study was no t a guideline quality study for oral exposure, and a new study is needed.

Special Study Honey bee adult

chronic toxicity (None) (Not applicable) No A chronic oral toxicity study with the adult honey bee is needed.

Special study

, OECD 237 Honey bee larvae

acute oral toxicity (None) (Not applicable) No An acute ora l toxicity study with the honey bee larvae is needed.

Special Study H oney bee larvae

chronic toxicity (None) (Not applicable) No A repeat dose toxicity study with honey bee larvae is needed.

Special Study Field trial of

residues in pollen
and nectar (None) (Not applicable) No A field trial measuring the residues
of sethoxydim in pollen and nectar is
needed

.

850.3030 Honey bee

residue on foliage (None) (Not applicable) No Acute contact LD 50 = 10 μg/bee; study is triggered, LD 50 is < 11 μg/bee.

Special Study

, OECD 75 Semi

- field

testing for pollinators (None) (Not applicable) Tiered Approach R esults of the Tier I studies could

trigger the higher Tier studies (Tier II and III) , see below.

850.3040 Field testing for

pollinators (None) (Not applicable) Tiered approach R esults of the Tier I studies could

trigger the higher Tier studies (Tier II and III), see below.

### 33

OCSPP
Guideline Data

Requirement Submitted

Studies (MRID) Study

Classifications Sufficient

for risk
assessment? Current Additional Data Need

850.4100 Seedling

Emergence 44204801 Supplemental

No Seedling emergence data is needed

to assess non

- target plants to Sethoxydim runoff exposure. It
needs to be confirmed that the available seedling emergence toxicity data is from a current market

T EP . The % a.i. is different (50.5% vs. 19.3%) than the test material
used for the latest vegetative vigor study (MRID 47691704)

. 43614603 Supplemental

850.4150 Vegetative Vigor 41885906 Supplemental

No , not for dicot plants plus 1 non

grass
monocot species MRID 41885906 , a Tier II

vegetative vigor study was conducted with 95.4% a.i., and not
with T EP as recommended in the

CFR . Although the second
submission MRID 47691704 is a
Tier II study for monocot plants using T EP (19.3% a.i.) , POAST ®

formulation

. N o acceptable vegetative vigor study is available for dicot plant species. Although sethoxydim, based on MOA is expected to impact monocot plants more than dicot plants, the available
data does not represent a realistic exposure scenario to dicot plants

, and a vegetative vigor toxicity study
with the current market TEP is still needed for dicot species and one

non

- grass monocot species

. 47691704 Supplemental



### Data Gaps

 OCSPP 850.1300: Freshwater invertebrate life

- cycle toxicity study using TGAI

 OCSPP 850.1350: Saltwater invertebrate life

- cycle toxicity study using TGAI

 OCSPP 850.1400: Saltwater fish early life

- stage toxicity study using TGAI

 OCSPP 850.2100: Acute Oral Toxicity with passerine species

 OCSPP 850.3030: Honey bee Toxicity of residues on foliage ; the a cute contact LD50 = 10 μg/bee; the study is triggered, if the LD50 is < 11 μg/bee

.

 OECD TG 213 and Non

- guid eline special studies: Honey bee adult acute and chronic oral toxicity studies

 OECD TG 237 and Non

- guideline special studies: Honeybee larval acute and chronic oral toxicity studies

 Non

- guideline special studies: Field trial measuring residues of sethoxydi m in pollen and

nectar

 Special study OECD TG 75 and OSCPP 850.3040: Semi

- field testing for pollinators and Field testing for pollinators (both studies that are conditionally required based on the
results of the Tier I

– laboratory based studies listed abov e; if needed these additional

### 34

field studies will be discussed pending the results of the acute and chronic adult and larval oral toxicity studies to honey bees).

 OCSPP 850.4100: Terrestrial plant seedling emergence toxicity study with current market TEP ( typical end

- use product). Additional information is needed to determine if the studies were conducted with the current market TEP for monocots and dicots. If not, a new Tier II seedling emergence study using the current market TEP is needed, and an

accep table Tier I test (at least is needed, unless a Tier II study is triggered for dicot plant species).

 OCSPP 850.4150: Terrestrial plant vegetative vigor Tier II toxicity study with (dicots and one additional species of monocots) to fulfill guideline. The only available vegetative vigor data for dicots was conducted with 95.4% a.i., and not with TEP stated i n the CFR

. Therefore, a vegetative vigor toxicity study with the current market TEP is still needed for dicot species

. In addition, to fulfill the gui deline, one additional monocot species is
also needed from a different Family (the three species tested represent Family Poaceae (grasses) only ).

Table 1 3 . Submitted Aquatic Ecological Effects Data for Sethoxydim Degradate

- Sulfone

Degradate Toxicity Data Gap

– Sulfone (terminal degradate , M2

- SO 2 

### )

 N on

- guideline study: aquatic vascular plant toxicity study with a grass species OCSPP
Guideline Data Requirement Submitted
Studies (MRID) Study

Classifications Sufficient

for risk
assessment? Current Additional Data

Need

NG Aquatic vascular

plant Toxicity Test using Glyceria

maxima (None) (Not applicable) No Based on the available data for the parent sethoxydim, degradate data is needed for the sethoxydim terminal degradate

– sulfone . Given the MOA of sethoxydim, an aquatic vascular plant study (using a grass species) is
needed

.

### 35

Honeybee Toxicity

Although sethoxydim is categorized as practically non

- toxic to adult honeybees on contact exposure basis, and by extension, to other beneficial terrestrial invertebrates on an acute exposure basis, there is considerable uncertainty regarding the potential effects of the compound on honeybee larval development and survival as well as potential for chronic effects. Th erefore, additional data on pollinators is needed to fully characterize the risk associated with sethoxydim use to all developmental stages of honeybees, as sensitivity may vary according to life

- stage and length of exposure (adult vs. larval and acute vs. chronic, respectively). Additional information is needed, but uncertainty associated with risks to honey bees need to be evaluated with more data to different life stages. Sethoxydim is systemic in plants so exposure via pollen and nectar is possible; a nd therefore, residues of pollen and nectar of crops are an additional data need. Open literature data is needed to help better characterize some uncertainties regarding potential
effects to bees and other non

- target terrestrial invertebrates. In additio n, higher tier effects toxicity tests ( i.e., semi

- field and/or field studies

– Tier II and Tier III, respectively) may be needed, based on the results of the larval and chronic adult toxicity studies. Higher tier studies
are recommended if the ratio of the EEC and larval or adult bee acute LD50> 0.4 or the ratio of
the EEC and the chronic NOAEC> 1 . Incident data and/or compelling open literature studies can also be used to support the need for higher tier studies. Should the screening level risk
assessment id entify that there are risk concerns to bees, mitigation measures may need to be considered or the registrant may need to conduct Tier II or Tier III effects studies ( e.g. OECD Guideline 75 and/or 850.3040 guideline studies) that reduce uncertainty by chara cterizing sethoxydim’s effects at the whole

- colony level 2



### .

2 http://www2.epa.gov/pollinator

- protection/pollinator

- risk

- assessment

- guidance

.

### 36

Study Title: Honey Bee Adult Acute Oral Toxicity Test ; Guideline Number: Special Study

– OECD 213 ; Test Substance: Sethoxydim

– TGAI Rationale for Requiring the Data

No data are available with which to assess the toxicity of sethoxydim to honey b ees on an acute oral exposure basis. Based on the registered use patterns, terrestrial invertebrates have the potential to be exposed by contacting and consuming sethoxydim residues. Therefore, the acute oral toxicity test is needed for EFED’s current screening

- level process for assessing potential effects to terrestrial
invertebrates.

The Agency finalized its framework to assess risk to pollinators (USEPA, 2014). EPA now requires
these studies for all use sites where potential exposure to pollinators may occur. Registrants may request a waiver of the studies if use practices significantly restrict exposure of the pesticide to bees.

The Agency does not have a guideline for the acute oral honey bee study; however, the OECD 213 guideline may be useful in protocol development. Practical Utility of the Data How will the data be used and how could the data impact the Agency’s future decision

making?
Data will be used to assess hazard and characterize risk to non

- target listed and non

- listed terrestrial invertebrate species. See Guidance for Assessing Pesticide Risks to Bees (USEPA, 2014) for
additional details.

If future endangered species risk assessments are performed without these dat a, the Agency would
have to assume that sethoxydim "may affect" endangered terrestrial insects directly (and endangered species from other taxa indirectly), and use of sethoxydim might need to be restricted in areas where endangered species could be expose d. The lack of these data will limit the flexibility the Agency and registrants have in coming into compliance with the Endangered Species Act and could result in use
restrictions for sethoxydim which are unnecessarily severe. In addition, the lack of thes e data may result in an uncertain assumed risk and potential mitigation of sethoxydim formulations under

FIFRA.

### 37

Study Title: Honey Bee Adult Chronic Oral Toxicity Study ; Guideline Number: Special Study

– Non

- guideline ; Test Substance: Sethoxydim

– TGAI Rationale for Requiring the Data No data have been submitted on the chronic toxicity of sethoxydim to adult honey bees. A study is needed to determine the chronic toxicity of the compound to adult honey bees, including mortality
and sub

- lethal ef

fects. This study is part of EFED’s current screening

- level process for determining potential effects to terrestrial invertebrates. Therefore, a non

- guideline honeybee larval toxicity study
is recommended. Although EPA has not developed a guideline for th is study and OECD has yet to finalize test guidance for chronic studies, efforts are currently underway to develop standardized guidelines for assessing effects from chronic (10

- day) exposures to adult bees in the laboratory. The registrant should submit a proposed protocol for review and approval by EFED prior to initiation of the study.

The Agency finalized its framework to assess risk to pollinators (USEPA, 2014). EPA now requires this study for all use sites where potential exposure to pollinators may occur. Registrants may request a waiver of the study if use practices significantly restrict exposure of the pesticide to bees. Practical Utility of the Data How will the data be used and how could the data impact the Agency’s future decision

making ?

The 10

- day toxicity study with young adult bees provides no

- observed adverse effect level (NOAEL)
and lowest

- observed adverse effect level (LOAEL) for assessing chronic effects. Data obtained from this study will be used in estimating chronic risk to i ndividual adult bees. Risk estimates based on these data will be considered along with other lines of evidence to determine whether higher

- tier studies are needed at the whole colony level.

These data are needed for the registration review risk assessment and for future endangered species assessments. The data would allow the Agency better characterize the potential for risk to insects (including beneficial pollinators) from the use of setho xydim . This data may help the Agency determine whether any mitigations are needed. If the registration review and any future endangered species risk assessments are performed without these data, the Agency would have to assume that sethoxydim "may affect " insects, including bees and beneficial pollinators, directly (and endangered species from other taxa indirectly), and uses of sethoxydim might need to be restricted in areas where pollinators could be exposed.

### 38

Study Title: Honey B ee Acute and Chronic Larvae Oral Toxicity Study ; Guideline Number: Special Study

– OECD 237 and Non

- Guideline ; Test Substance: Sethoxydim

– TGAI Rationale for Requiring the Data No data have been submitted on the toxicity of sethoxydim to honey bee larvae. L arval toxicity study are needed to determine the toxicity of the compound to developing brood ( i.e ., larvae and pupae)

, including mortality and adult emergence . This study is part of EFED’s current screening

level process for determining potential effects to terrestrial invertebrates. Although EPA has not developed a guideline for this study, the 21

- day larval toxicity study currently under development by OECD provides both acute and chronic oral toxicity data on developing bee brood and (when this guidanc e is finalized) may be used to satisfy the requirement for both acute and chronic oral toxicity to honey bee larvae. Registrants are at liberty though to submit a separate acute (single dose) larval toxicity study following OECD TG 237 as well as the 21

- d ay repeat dose chronic toxicity study. For the chronic toxicity study though, since no guideline is available, it is recommended that the registrant should submit a proposed protocol for review and approval by EFED prior to initiation of the study.

The Agency finalized its framework to assess risk to pollinators (USEPA, 2014). EPA now requires these studies for all use sites where potential exposure to pollinators may occur. Registrants may request a waiver of the studies if use practices significantly restrict exposure of the pesticide to bees. Practical Utility of the Data How will the data be used and how could the data impact the Agency’s future decision

making?

The 21

- day larval toxicity study under development by OECD provides both acute and chronic toxicity data on developing bee brood and will yield a median lethal dose (LD 50 ) for assessing acute toxicity during the early part of the study as well as a 21

- day no

- observed adverse effect level (NOAEL) and lowest

- observed adverse effect level ( LOAEL) for assessing chronic effects. Effects on survival and development (adult bee emergence) from repeat exposures to the active ingredient will be used in estimating chronic risk to individual brood. Risk estimates based on these data will be
conside red along with other lines of evidence to determine whether higher

- tier studies are needed at the whole colony level.

Data will be used to assess risk to non

- target listed and non

- listed terrestrial invertebrate species. This study would allow the Agency to refine the screening

- level hazard assessment for beneficial
terrestrial invertebrates. The effects data will be used to determine the potential for adverse effects on beneficial terrestrial invertebrates through direct effects on larval bees. See Guidan ce for Assessing Pesticide Risks to Bees (USEPA, 2014) for additional details. These data are needed for the registration review risk assessment and for future endangered species assessments. The data would allow the Agency better characterize the potent ial for risk to insects (including beneficial pollinators) from the use of sethoxydim . This data may help the Agency determine whether any mitigations are needed. If the registration review and any future endangered species risk assessments are performed without these data, the Agency would have to assume that sethoxydim "may affect" insects, including bees and beneficial pollinators, directly (and endangered species from other taxa indirectly), and uses of sethoxydim might need to be restricted in areas where pollinators could be exposed.

### 39



## 10. References

United States Environmental Protection Agency (USEPA). 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs

. U.S. Environmental Protection Agency, Office of Pesticide Programs, Environmen tal Fate and Effects
Division . Available at http://www.epa.gov/espp/consultation/ecorisk

- overview.pdf

USEPA. 2005. M emorandum “ EFED ’s Rereg istration Eligibility Decision Chapter for Sethoxydim (Chemical #121001, DP Barcode D312568, D312561 ).” April 4, 2005

. Office of Pesticide Programs, U.S. Environmental Protection Agency, Washington D.C.

USEPA. 2006. M emorandum “EFED Risk Assessmen t for New Uses of Sethoxydim on Buckwheat, Okra, Dill, Borage, Root Vegetables, and Turnip Greens .” (DP313456 & 314420). June 26, 2006). Office of Pesticide Programs, U.S. Environmental Protection Agency, Washington D.C.

USEPA. 2007 a . ECOTOXicology Database. Office of Research and Development National Health and Environmental Effects Research Laboratory’s (NHEERL’s) Mid

- Continent Ecology Division (MED). http://cfpub.epa.gov/ecotox/

USEPA. 2014 a . Guidance for Assessing Pesticide Risks to Bees. U.S. Environmental Protection Agency, Office of Pesticide Programs; Health Canada Pest Management Regulatory Agency; and California Department of Pesticide Regulation. Jun. 23, 2014. Available at http://www2.epa.gov/pollinator

- protection/pollinator

- risk

- assessment

- guidance

.

USEPA. 2014 b . Wendel, C. and J. Lin. Sethoxydim: Section 3 New Use Risk Assessment for

IR

- 4 Petition on Fescue, Oilseeds, Fruits, and Vegetables DP barcode 418333. U.S. Environmental Protection Agency, Office of Chemical Safety and Pollution Prevention, Environmental Fate and Effects Division. Memorandum to the Registration Division.

Dec. 1 9, 2014.



## a. Submitted Environmental Fate Studies

MRID Citation Reference

00042821 Nippon Soda Company, Limited (1980) Photodegradation of NP

- 55 by Sunlight.

(Unpublished study received Aug 4, 1980 under 0G2396; submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL: 099539

- N)

00047649 Nippon Soda, Limited (1979) Photodegradation of NP

- 55: RD

- 7930. (Unpublished study

received Aug 4, 1980 under 0G2396; submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:099535

- F)

00130712 BASF Wyandotte Corp. (1983) The Significance of Hydroxylated Residues of Poast

Herbicide. Interim rept. (Unpublished study received Jul 22, 1983 under 7969

- 58;
CDL:251045

- A)

### 40

MRID Citation Reference

41475207 Soeda, Y.; Shiotani, H. (1988) Sethoxydim

-- Hydrolysis: Final Report: Lab Project

Number: NI SSO EC

- 121/BASF 88/5040. Unpub lished stu dy prepared by Nippon Soda Co., Ltd., Environmental Toxicology Lab. 29 p.

92166033 Soeda, Y. (1990) BASF Corporation Phase 3 Summary of MRID 41475207. Sethoxydim

- Hydrolysis: Project EC

- 121; REG DOC #BASF 90/6040. Prepared by NIPPON SOAD CO. LTD. 11 p.

00042819 Nippon Soda Company, Limited (197 9) Hydrolysis of NP

- 55. (Unpub lished study

received Aug 4, 1980 under 0G2396; submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:099539

- L)

41475208 Soeda, Y. ; Shiotani, H. (1988) Sethoxydim: Photodegradati on in Water: Final Report:

Lab Project Number: NISSO EC

- 125: BASF 88/ 5047. Unpublished study prepared by Nippon Soda Co., Ltd., Environmental Toxicology Lab. 35 p.

92166034 Soeda, Y. (1990) BASF Corporation Phase 3 Summary of MRID 41475208. Sethoxydim

- Photodegradation in Water: Project EC

- 125; REG DOC #BASF 90/6041. Prepared by NIPPON SODA CO. LTD. 13 p.

00100540 Huber, R. (1981) Investigations on the Photolytic Degradation of BAS 9052 H (NP 55)

on Soil: Lab. Communication No. 903. (Un published study received Apr 15, 1982 under

7969

- 58; prepared by BASF, AG, submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:070822

- E)

41475209 Soeda, Y.; Shiotani, H. (1988) Sethoxydim: Photodegradation on Soil: Final Report: Lab

Project Number: NISSO EC

- 142: BASF 88/51 06. Unpublished study prepared by Nippon Soda Co., Ltd., Environmental Toxicology Laboratory. 37 p.

92166035 Soeda, Y. (1990) BASF Corporation Phase 3 Summary of MRID 41475209. Sethoxydim

- Photodegradation on Soil: Project EC

- 14 2; REG DOC #BASF 90/6042. Prepared by NIPPON SODA CO. LTD. 14 p.

00042480

00100541 Nippon Soda Company, Limited (1980) Photolysis of NP

- 55 under Anaerobic and

Aerobic Conditions. (Unpublished study including published data, received Aug 4, 1980
under 0G2396; submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:099539

- M)

Redeker, J.; Hamm, R. (1981) Degradation of BAS 9052 H (NP 55) in a Loamy Sand under Aerobic, Anaerobic and Sterile

- aerobic Conditions: Report No. 1804. (Unpublished study received Apr 15, 1982 under 7969

- 58; prepared by BASF, AG, submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:070822

- F)

41475210 Shiotani, H. (1989) Sethoxydim: Aerobic Soil Metabolism: Final Report: Lab Project

Number: NISSO EC

- 175: BASF 89/5135. Unpublis hed study prepared by Nippon Soda Co., Ltd., Environmental Toxicology Lab. 57 p.

92166036 Soeda , Y. (1990) BASF Corporation Phase 3 Summary of MRID 41475210. Sethoxydim

- Aerobic Soil Metabolism: Project EC

- 175; REG DOC #BASF 90/6043. Prepared by NIPPON SODA CO. LTD. 13 p.

41475211 Soeda, Y. ; Shiotani, H. (1989) Sethoxydim: Anaerobic Soil Meta

- bo lism: Final Report:

Lab Project Number: NISSO EC

- 158: BASF 89/ 5000. Unpublished study prepared by Nippon Soda Co., Ltd., Environmental Toxicology Lab. 45 p.

### 41

MRID Citation Reference

92166037 Soeda, Y. (1990) BASF Corporation Phase 3 Summary of MRID 41475211. Sethoxydim

- Anaero bic Soil Metabolism: Project EC

- 158; REG DOC #BASF 90/6044. Prepared by NIPPON SODA CO. LTD. 14 p.

42165603 Shiotani, H. (1991) Sethoxydim: Anaerobic Aquatic Metabolism: Lab Project Number:

91/5113. Unpublished study prepared by Nippon Soda Co., Ltd. 78 p.

42165604 Shiotani, H. (1991) Sethoxydim: Aerobic Aquatic Metabolism: Lab Project Number:

89/5194. Unpublished study prepared by Nippon Soda Co., Ltd. 74 p.

00042823 Huber, R. (1980) Investigations into the Aerobic Soil Metabolism of Bas 9052 H/NP 55:

Laboratory Report No. 1692. (Unpublished study received Aug 4, 1980 under 0G2396; prepared by BASF, AG, West Germany, submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:099539

- P)

00100542 Dams, W. (1981) Adsorption Behaviour of Active Ingredients of Plant Protection

Products in the System Soil / Water. (Unpublished study received Apr 15, 1982 under

7969

- 58; prepared by BASF, AG, submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:070822

- G)

41475212 Soeda, Y.; Shiotani, H. (1988) Sethoxydim: Batch Equilibrium (Adsorption/ Desorption):

Final Report: Lab Project Number: NISSO EC

- 149: BASF 88/5120. Unpublished study prepared by Nippon Soda Co., Ltd., Environmental Toxicology Lab. 64 p.

92166038 Soeda, Y. (1990) BASF Corpo ration Phase 3 Summary of MRID 41475212. Sethoxydim

- Batch Equilibrium (Adsorption/Desorption): Project EC

- 149; REG DOC #BASF 90/6045. Prepared by NIPPON SODA CO. LTD. 13 p.

41510608 Single, Y.; Burkey, J. (1989) Poast Herbicide Field Soil Dissipation Study for Forage

Crop Use in California

-- Soil Analyses: Lab Project Number: A8944: BASF 89

- 5145. Unpublished study prepared by Nippon Soda Co., Ltd. in cooperation with BASF. 55 p.

41510609 Single, Y.; Burkey, J. (1989) Poast Herbicide Field Soil Dissipa tion Study for Row Crop

Use in California

-- Soil Analyses: Lab Project Number: A8943: BASF 89

- 5156. Unpublished study prepared by Nippon Soda Co., Ltd. in cooperation with BASF. 57 p.

41510610 Rotondaro, A. (1989) Sethoxydim Row Crop Use: Terrestrial Fiel d Dissipation: Lab

Project Number: RCN NO. 88063: PROTOCOL NO. M8714: BASF 89

- 5147. Unpublished study prepared by Pan

- Agricultural Labs., Inc. 232 p.

41510611 Rotondaro, A. (1989) Sethoxydim Forage Crop Use: Terrestrial Field Dissipation: Lab

Project Num

ber: RCN NO. 88064: M8713: EF

- 88

- 28: 89

- 5160. Unpublished study prepared by Pan

- Agricultural Labs., Inc. 186 p.

44311001 Burkey , J. (1997) Freezer Storage Stability of Sethoxydim Residues in Soil: Amendment

to Final Report: Lab Project Number: 97/5287: A892141: A8921. Unpublished study prepared by BASF Corp. 42 p.

44352401 Beutel, P.; Huber, R. (1982) Investigation of Freezer St orage Stability of BAS 9052H and

Metabolites in Soil Comparing (carbon 14)

- Results Obtained with BASF Total Method No. 181: Lab Project Number: 82/10029: 1823. Unpublished study prepared by BASF Aktiengesellschaft. 28 p.

### 42

MRID Citation Reference

92166039 Eubanks, M. (1990) BASF Corporation Phase 3 Summary of MRID 00100543 and

Related MRIDs 41510608, 41510609, 41510610. Poast Herbicide

- Terrestrial Field Dissipation Studies in: California, Minnesota, Illinois and Mississippi: REG DOC #BASF 90/6046. Prepared by BASF RESEARCH STATI ON. 23 p.

42165605 Eubanks, M. (1991) Poast Herbicide (Sethoxydim) Aquatic Dissipation Study: Lab

Project Number: 91/5153. Unpublished study prepared by BASF Corp. Chemicals Division and Others. 535 p.

00042825

92166040 Nippon Soda Company, Ltd.

Looper , G.; Winkler, V. (1990) BASF Corporation Phase 3 Summary of MRID 00042825 and Related MRIDs 41510612. Sethoxydim: Confined Rotational Crops: REG DOC #BASF 90/6070 and #81/5053. Prepared by NIPPON SODA CO. LTD. 27 p.

41510612 Clark, J.; Adamson , S. (1981) Uptake of BAS 9052

- | Carbon 14| (NP

- 55) Residues by

Rotational Crops Under Field Conditions: Lab Project Number: PM

- 33: 81

- 5053. Unpublished study prepared by BASF Corp. 20 p.

00087573 Clark, J.R.; Adamsbaum, S.N. (1981) Uptake of BAS 9052H

- ^14IC (NP

- 55) Residues by

Rotational Crops under Field Conditions: Laboratory Report No. PM

- 33. (Unpublished study received Dec 2, 1981 under 7969

- EX

- 14; submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:246346

- A).

42118001

A

- B McKenna, E. (1991) Bioaccumula tion and Metabolism of | carbon 14|

- Sethoxydim in

Bluegill Sunfish: Lab Project No: M9018: M9121. Unpublished study prepared by BASF Corp. 112 p.

00 100537 Vilkas, A.G.; Kuc, W.J. (1981) 14C

- BAS 9052: Bluegill Sunfish, Lepomis macrochirus

Rafinesque; Bioc oncentration Study: UCCES Project No. 11507

- 81. (Unpublished study received Apr 15, 1982 under 7969

- 58; prepared by Union Carbide Corp. Environmental Services, submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:070822

- B)

.

00 100538 Vilkas, A.G.; Kuc , W.J. (1981) 14C

- BAS 9052: Channel Catfish, Ictalurus punctatus

(Rafinesque), Bioconcentration Study: UCCES Project No. 11507

- 82. (Unpublished study received Apr 15, 1982 under 7969

- 58; prepared by Union Carbide Corp. Environmental Services, submitted by BASF Wyandot te Corp., Parsip pany, N.J.;
CDL:070822

- C)

.

41475213 Akesson, N. (1982) Poast Simulated Field Drift Trials: Final Report: Lab Project

Number: UC DAVIS RPT. NO. 1: BASF 85/5046. Unpublished study prepared by Univ. of California, Davis, Dept. of Agric. Engineering. 59 p.

41475213 Akesson , N. (1982) Poast Simulated Field Drift Trials: Final Report: Lab Project

Number: UC DAVIS RPT. NO. 1: BASF 85/5046. Unpublished study prepared by Univ. of California, Davis, Dept. of Agric. Engineering. 59 p.

92166050 Eubanks, M. (1990) BASF Corporation Phase 3 Summary of MRID 41475213.

Sethoxydim

- Simulated Field Trials in California: BASF DOC No. 85/5046, BASF 90/6048. Prepared by UNIV. OF CALIFORNIA, DEPT. OF AGR. ENGINEERING. 17p.

### 43

MRID Citation Reference

100543 Craven, D.A. (1982) Determination of BAS 9052 H and Its Met abolite Residues in Soil

Samples: Report No. CR

- 5; BWC Project No. IX

- 2

- G

- 229. (Unpublished study, including analytical method no. 31, received Apr 15, 1982 under 7969

- 58; prepared by Craven Laboratories, Inc., submitted by BASF Wyandotte Corp., Parsippan y, N.J.;
CDL:070822

- H)

.

100544 Nippon Soda Company, Limited (1981) Octanol / Water Partition Co

- efficient of NP

- 55

Related Co mpounds. (Unpublished study re ceived Apr 15, 1982 under 7969

- 58; submitted by BASF Corp., Parsippany, N.J.; CDL:070822

- I)

.

401 95103 Paulick, R. (1987) Freezer Stora ge Stability of Sethoxydim Meta bolites MSO and 5

- OH

MSO2 in Potatoes: BASF Doc. No. 87/5008: Rept. No. A8705. Unpublished stu dy prepared by Craven Laborato ries, Inc. 30 p.



## b. Submitted Ecological Toxicity Studies

MRID Citation Reference

00042813 Fink, R.; Beavers, J.B.; Grimes, J.; et al. (1979) Final Report: Acute Oral LD50

- Mallard

Duck: Project No. 147

- 120. (Unpublished study received Aug 4, 1980 under 0G2396; prepared by Wildlife International, Ltd. and Washington College, submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:099539

- D).

92166002 Eubanks, M. (1990) BASF Corporation Phase 3 Summary of MRID 00042813. Sethoxydim

- Avian Acute LD 50 Test

- Mallard Duck: Project 147

- 120. Prepared by WILDLIFE

INTERNAT IONAL LTD. 16 p.

00042814 Fink, R.; Beavers, J.B.; Grimes, J.; et al. (1979) Final Report: Eight

- Day Dietary LC50

-

Bobwhite Quail: Project No. 147

- 118. (Unpublished study received Aug 4, 1980 under 0G2396; prepared by Wildlife International, Ltd. and Washi ngton College, submit

- ted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:099539

- E).

00072862 Fink, R.; Beavers, J.B.; Grimes, J.; et al. (1979) Final Report: Eight

- Day Dietary LC50

-

Mallard Duck: Project No. 147

- 119. (Un

- published study received Aug 4, 1980 under 0G2396; prepared by Wildlife International, Ltd. and Washington College, submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:099539

- F).

92166003 Eubanks, M. (1990) BASF Corporation Phase 3 Summary of MRID 00042814 and Related

MRIDs 00072 862. Sethoxydim

- Avian Acute Dietary LC50 Test Mallard Duck and Bobwhite Quail: Project 147

- 118 and Project 147

- 119; REG DOC #BASF 90/6002. Prepared by WILDLIFE INTERNATIONAL LTD. 16 p.

00162823 Beavers, J. (1986) Pyridate Technical: A Pilot Reproductio n Study with the Bobwhite

(Colinus virginianus): Final Report: Wildlife International Ltd. Project No. 217

- 105. Unpublished study pre

- pared by Wildlife International Ltd. 27 p.

44003401 Munk, R. (1996) Sethoxydim: One

- Generation Reproduction Study on t he Bobwhite Quail

(Colinus virginianus) by Administration in the Diet: Lab Project Number: 96/10152: 08B0155/926020: PCP03583. Unpublished study prepared by BASF Aktiengesellschaft. 382p.

### 44

MRID Citation Reference

44003402 Beavers, J.; Chafey , K.; Mitchell, L. et al. (1996) Sethoxydim: A Reproduction Study with

the Mallard: Lab Project Number: 96/10105: 147

- 168: 72W0155/929040. Unpublished study prepared by Wildlife Int'l. Ltd. 153 p.

48000901 Zok, S. (2009) BAS 562 H (Sethoxydim)

- 1

- Gener ation Reproduction Study on the Mallard

Duck (Anas platyrhynchus) by Administration in the Diet. Project Number: 72W0530/085045, 302019, 2009/1100351. Unpublished study prepared by BASF SE: Experimental Toxicology and Ecology. 403 p.

41885901 Bowman, J.; Howell, R. (1991) Acute Toxicity of Poast Herbicide (BAS 9052 06 H) to

Blugeill (Lepomis macrochirus): Lab Project Number: 90/5135. Unpublished study prepared by ABC Laboratories, Inc. 28 p.

41885902 Bowman, J.; Howell, R. (1991) Acute Toxicity of Poas t Herbicide (BAS 9052 06 H) to

Rainbow Trout (Oncorhynchus mykiss): Lab Project Number: 90/5136. Unpublished study prepared by ABC Laboratories, Inc. 28 p.

92166004 Eubanks, M. (1990) BASF Corporation Phase 3 Summary of MRID 00072863. Sethoxydim

Acute T oxicity Test for Freshwater Fish

- Bluegill Sunfish: UCCES Project No. 11506

- 17

- 24; REG DOC BASF 90/6003. Prepared by UNION CARBIDE CORP. 11p.

00042815 Vilkas, A.G.; Seminara, J. (1979) The Acute Toxicity of Bas 9052 H Technical (97.3%) to

the Rainbow T rout, Salmo gairdneri Richardson: UCES Project No. 11507

- 17

- 25. (Unpublished study received Aug 4, 1980 under 0G2396; prepared by Union Carbide Corp., submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:099539

- H).

92166005 Eubanks, M. (1990) BASF Co rporation Phase 3 Summary of MRID 00042815. Sethoxydim

Acute Toxicity for Freshwater Fish

- Rainbow Trout UCCES Project No. 11506

- 17

- 25; REG DOC #BASF 90/6004. Prepared by UNION CARBIDE CORP. 12 p.

47691701 Aufderheide, J. (2009) BAS 562 05 H (POAST): Acute Toxicity Test to the Fathead

Minnow, Pimephales promelas, Determined Under Flow

- Through Test Conditions. Project Number: 64117, 356157, 2009/7000068. Unpublished study prepared by ABC Laboratories,
Inc. 46 p.

00072863 Vilkas, A.G.; Seminara, J. (1980) The Acute Toxicity of Tech BAS 9052 Lot PN

- 10

- 1 to the

Bluegill Sunfish, Lepomis macrochirus Rafinesque: UCES Project No. 11506

- 17

- 24. (Unpublished study received Aug 4, 1980 under 0G2396; prepared by Union Carbide Corp., submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL: 099539

- G).

41885903 Blasberg, J.; Hicks, S.; Howell, R. (1991) Acute Toxicity of Poast Herbicide to Daphnia

magna: Lab Project Number: 90/5137. Unpublished study prepared by ABC La boratories, Inc. 29 p.

00042816 Vilkas, A.G.; Morrissey, A.E. (1979) The Acute Toxicity of Bas 9052 H Technical (97.3%)

Lot No. 23

- 9051

- TA to the Water Flea Daphnia magna Straus: UCES Project No. 11506

- 17

- 23. (Unpublished study received Aug 4, 1980 unde r 0G2396; prepared by Union Carbide Corp., submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:099539

- I).

### 45

MRID Citation Reference

92166006 Eubanks, M. (1990) BASF Corporation Phase 3 Summa ry of MRID 00042816. Sethoxydim

Acute Toxicity Test for Fresh water Invertebrates

- Water Flea: UCCES Project No. 11506

- 17

- 23; BASF DOC # 90/6005. Prepared by UNION CARBIDE CORP. 11 p.

41510602 Ward, T.; Boeri, R. (1989) Static Acute Toxicity of Poast Herbicide to the Sheepshead

Minnow, Cyprinodon variegatus: Lab P roject Number: 8902

- B: BASF 89

- 5162. Unpublished study prepared by EnviroSystems. 28 p.

41510603 Ward, T.; Boeri, R. (1989) Static Acute Toxicity of Poast Herbicide to the Blue Crab,

Callinectes sapidus: Lab Project Number: 8903

- B: BASF 89

- 5163. Unpublis hed study prepared by EnviroSystems. 28 p.

41510604 Ward, T.; Boeri, R. (1989) Static Acute Toxicity of Poast Herbicide to the Mysid,

Mysidopsis bahia: Lab Project Number: 8901

- B: BASF 89

- 5164. Unpublished study prepared by EnviroSystems. 28 p.

41607207 Ward, T.; Boeri, R. (1990) Static Acute Toxicity of Poast Herbicide (...) to Bivalve Mollusc

Embryos and Larvae: Lab Project Number: 90/5045. Unpublished study prepared by EnviroSystem Div., Resource Analysts, Inc. 22 p.

42315101 Ward, T.; Boeri, R. ( 1992) Static Acute Toxicity of Sethoxydim (BAS 9052 H) to the

Sheepshead Minnow, Cyprinodon variegatus: Lab Project Number: 91129

- B: 39624. Unpublished study prepared by Resource Analysts, Inc. and ABC Laboratories. 43 p.

42315102 Ward, T.; Boeri, R. (19 92) Static Acute Toxicity of Sethoxydim (BAS 9052 H) to the

Mysid, Mysidopsis bahia: Lab Project Number: 91127

- B: 39623. Unpublished study prepared by Resource Analysts, Inc. and ABC Laboratories. 43 p.

42537401 Lintott, D. (1992) Sethoxydim

- Technical (B AS 562 H): Acute Toxicity to Embryos and

Larvae of the Eastern Oyster, Crassostrea virginica under Static Test Conditions: Lab Project Number: 92/5157: 92079: J9203014. Unpublished study prepared by Toxikon Environmental Sciences and BASF. 45 p.

92166007 Eubanks, M. (1990) BASF Corporation Phase 3 Summary of MRID 41510602. Poast

Herbicide

- Acute Toxicity Test for Estuarine Fish

- Sheepshead Minnow: Project No. 8902

- B; REG DOC #BASF 90/6006. Prepared by ENVIROSYSTEMS DIV., RESOURCE ANALYSTS INC. 13 p.

92166008 Eubanks, M. (1990) BASF Corporation Phase 3 Summary of MRID 41510603. Poast

Herbicide

- Acute Toxicity Test for Estuarine Species

- Blue Crab: Project No. 8903

- B; REG DOC #BASF 90/6007. Prepared by ENVIROSYSTEMS DIV. RESOURCE ANALYSTS. 13 p.

92 166009 Eubanks, M. (1990) BASF Corporation Phase 3 Summary of MRID 41510604. Poast

Herbicide

- Acute Toxicity Test for Shrimp

- Mysid: Project No. 8901

- B; REG DOC #BASF 90/6008. Prepared by ENVIROSYSTEMS DIV. RESOURCES ANALYSTS, INC. 13 p.

### 46

MRID Citation R eference

43614601 Graves, W.; Mank, M.; Swigert, J.; et al. (1995) Sethoxydim: An Early Life

- Stage Toxicity

Test with the Sheepshead Minnow (Cyprinodon variegatus ): Lab Project Number: 95/5014:

147A

- 123: A008.068. Unpublished study prepared by Wildlife International Ltd. and Huntingdon Analytical Services. 107 p.

43614602 Boeri, R.; Kowalski, P.; Ward, T.; et al. (1995) Chronic Toxicity of Sethoxydim to the

Mysi d, Mysidopsis bahia: Lab Project Number: 95/5030: A008.059: 485

- BA. Unpublished study prepared by T.R. Wilbury Labs, Inc. and Huntingdon Analytical Services. 95 p.

47691702 Aufderheide, J. (2009) BAS 562 H: Early Life

- Stage Toxicity Test with the Fathea d

Minnow, Pimephales promelas, Under Flow

- Through Test Conditions. Project Number: 64012, 302018, 2009/7000078. Unpublished study prepared by ABC Laboratories, Inc. 69 p.

47691703 Aufderheide,J. (2009) BAS 562 05 H (POAST): Early Life

- Stage Toxicity Test with the

Fathead Minnow, Pimephales promelas, Under Flow

- Through Conditions. Project Number: 64010, 346309, 2009/7000077. Unpublished study prepared by ABC Laboratories, Inc. 83 p.

44204801 Maggi, V.; Jackson, S. (1994) Tier I: Determination of the Phyt otoxic Effects of Poast on

Seed Germination/Seedling Emergence of Nontarget Plants: Final Report: Lab Project
Number: ER93043: 94/5191: CAR 166

- 93. Unpublished study prepared by California Agricultural Research, Inc. 122 p.

41400103 Hughes, J. (1980) Tox icity of BAS 9052 O H (Poast) to Duckweed: Lab Project Number:

85/5052. Unpublished study prepared by Union Carbide Corp. Environmental Services. 33p.

41400104 Hughes, J. (1981) Toxicity of BAS 9052 O H (Poast) to Algae and Duckweed: Lab Project

Number: 85/5051. Unpublished study pre

- pared by Union Carbide Corp., Environmental Services. 10 p.

41400105 Hughes, J. (1981) Toxicity of BAS 9052 O H (Poast) to Skeletonema costatum: Lab Project

Number: 85/5054. Unpublished study prepared by Union Carbide Cor p. Environmental Services. 26 p.

41400106 Hughes, J. (1980) Toxicity of BAS 9052 O H (Poast) to Selenastrum capricornutum: Lab

Project Number: 85/5056. Unpublished study prepared by Union Carbide Corp. Environmental Services. 26 p.

41400107 Hughes, J. (1981) Toxicity of BAS 9052 O H (Poast) to Navicula seminulum Grun: Lab

Project Number: 85/5053. Unpublished study prepared by Union Carbide Corp. Environmental Services. 27 p.

41400108 Hughes, J. (1981) Toxicity of BAS 9052 O H (Poast) to An abaena flos

- aquae: Lab Project

Number: 85/5055. Unpublished study pre

- pared by Union Carbide Corp. Environmental Services. 27 p.

41400101 Krieg, K. (1980) Seed Germination Tests for BAS 9052 O H (Poast): Tier 2: Lab Project

Number: 85/5049. Unpublished study prepared by BASF Aktiengesellschaft, Agricultural Research Station. 18 p.

### 47

MRID Citation Reference

41400102 Ludwig, J. (1980) Poast Phytotoxicity Studies: Lab Project Number: 85/5047. Unpublished

study prepared by BASF Wyandotte Corp., Agricultura l Research Farm. 23 p.

41885906 Chetram, R. (1991) Tier 2 Vegetative Vigor Nontarget Phytotoxicity Study Using

Sethoxydim (BAS 9052 H Tech.a.i): Lab Project Number: 90/5138. Unpublished study prepared by Pan

- Agricultural Labs, Inc. 150 p.

43614603 Maggi, V.; Jackson, S. (1994) Determination of the Phytotoxic Effects of Poast on Seed

Germination/Seedling Emergence of Nontarget Gramineae Plants: Final Report: Lab Project
Number: 94/5190: CAR 168

- 93: 93095. Unpublished study prepared by California Agr icultural Research, Inc. 118 p.

43614604 Jackson, S.; Maggi, V. (1994) Determination of the Phytotoxic Effects of Poast on

Vegetative Vigor of Nontarget Gramineae Plants: Final Report: Lab Project Number:
95/5029: CAR 175

- 94: ER95003. Unpublished study prepared by California Agricultural Research, Inc. 131 p.

92166030 Eubanks, M. (1990) BASF Corporation Phase 3 Summary of MRID 41400101. Sethoxydim

Seed Germination/Seedling Emergence Nontarget Phytotoxicity Study: Project 85/5049;
REG DOC #BASF 90/6037 . Prepared by BASF AKTIENGESELLSCHAFT. 14 p.

47691704 Bergfield, A. (2009) BAS 562 05 H (POAST): Effects on the Vegetative Vigor of Non

Target Terrestrial Plants (Tier II). Project Number: 64011, 302015, 2009/7000073. Unpublished study prepared by ABC La boratories, Inc. 64 p.

43614605 Thompson, S.; Swigert, J.; Jackson, S. (1994) Sethoxydim 99.8% Tech: A Tier II 14

- Day

Toxicity Test with Duckweed (Lemna gibba): Lab Project Number: 94/5067: 147A

- 109A: A008.047. Unpublished study prepared by Wildlife Inte rnational Ltd. and Huntingdon Analytical Services. 63 p.

43614606 Thompson, S.; Swigert , J.; Jackson, S. (1994) Sethoxydim 99.8% Tech: A Tier II 5

- Day

Toxicity Test with the Freshwater Diatom (Navicula pelliculosa): Lab Project Number:
94/5068: 147A

- 110: ER94015. Unpublished study prepared by Wildlife International Ltd. and Huntingdon Analyt ical Services. 60 p.

43614607 Thompson, S.; Roberts, C.; Swigert, J.; et al. (1994) Sethoxydim 99.8% Tech: A Tier II 5

-

Day Toxicity Test with the Freshwater Alga (Selenastrum capricornutum): Lab Project
Number: 94/5069: 147A

- 112: A008.049. Unpublished s tudy prepared by Wildlife International Ltd. and Huntingdon Analytical Services. 59 p.

43614608 Thompson, S.; Swigert, J.; Jackson, S. (1994) Sethoxydim 99.8% Tech: A Tier II 5

- Day

Toxicity Test with the Freshwater Alga (Anabaena flos

- aquae): Lab Project Number:
94/5071: 147A

- 111B: A008.050. Unpublished study prepared by Wildlife International Ltd. and Huntingdon Analytical Services. 60 p.

43626101 Thompson, S.; Swigert, J. (1994) Sethoxydim 99.8% Tech: A Tier II 5

- Day Toxicity Test

with the Marine Diat om (Skeletonema costatum): Lab Project Number: 147A

- 108: 93129: ER 94016. Unpublished study prepared by Wildlife International Ltd. and Huntingdon Analytical Services. 59 p.

### 48

MRID Citation Reference

48000902 Knauert , S. 2009. Effect of BAS 562 05 H on growth of the aquatic plant Glyceria maxima

(including Amendment No. 1). Unpublished study performed by BASF SE, BASF Agricultural Center Limburgerhof, Crop Protection Division, Ecology and Environmental Analytics, Lim

burgerhof, Germany. Study Identification No. 302016. Study sponsored by BASF Corporation, Research Triangle Park, North Carolina. Study completed October 1, 2009. Amendment No. 1 completed February 17, 2010.

92166031 Eubanks, M. (1990) BASF Corporatio n Phase 3 Summary of MRID 41400103 and Related

MRIDs 41400104, 41400105, 41400106, 41400107, 41400108. Poast Herbicide

- Growth and Reproduction of Aquatic Plants

- Duckweed, Green Alga, Blue

- green Alga, Marine Diatom and Freshwater Diatom: Projects 11507

- 83

- 01, 11507

- 83

- 02, 11507

- 83

- 03, 11507

- 83

- 04 11507

- 83

- 05; REG DOC #BASF 90/6038. Prepared by UNION CARBIDE CORP. 16p.

41510607 Nippon Soda Co., Ltd. (1981) Effects of NP

- 55 on Honey Bees: Lab Project Number: BASF

81/9013. Unpublished study prepared by Ni ppon Soda Co., Ltd. 9 p.

92166032 Soeda, Y. (1990) BASF Corporation Phase 3 Summary of MRID 41510607. Sethoxydim

-

Effects on Honey Bees: Project RD

- 8164; REG DOC #BASF 90/6039. Prepared by NIPPON SODA CO. LTD. 11 p.

00042817 Nippon Soda Company, Limi ted (1980) The Influence of NP

- 55 on Honey Bees. Prelim.

rept. (Unpublished study received Aug 4, 1980 under 0G2396; submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:099539

- J).

00042812 Clark, J.R. (1980) Wildlife Toxicology: Impact of Bas 9052 O H on Fish, Wildlife, and

Bees. Summary of studies 099539

- D through 099539

- J. (Unpublished study received Aug 4, 1980 under 0G2396; submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL: 099539

- C).

00100536 BASF Wyandotte Corporation (1982) Nontarget Hazard Assessment: Impact of Poast on

Fish, Wildlife and Bees. Summary of studies 070822

- B and 070822

- C. (Unpublished study received Apr 15, 1982 under 7969

- 58; CDL: 070822

- A).

48033008 Kojima, H.; Katsura, E.; Takeuchi, S.; et al. (2004) Screening for Estrogen and Androgen

Receptor Activities in 200 Pesticides by In Vitro Reporter Gene Assays Using Chinese Hamster Ovary Cells. Environmental Health Perspectives 112(5): 524

- 531.

00045847 Nishibe, T.; Souma, S. (1979) Acute Oral Toxicity of NP

- 55 in Rats . (Unpublished study

received Aug 4, 1980 under 0G2396; prepared by Nippon Soda Co., Ltd., Japan, submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:099536

- C).

00046326 Gelbke,?; Jackh,?; Freisberg, ?. (1980) Report on the Study of the Acute Oral Toxicity of Bas

9052 O H in the Rat. (Translation from German; unpublished study received Sep 18, 1980
under 7969

- EX

- 14; prepared by BASF, AG, submitted by BASF Wyandotte Corp., Parsippany, N.J.; CDL:243319

- A).

### 49

MRID Citation Reference

00045849 Nishibe, T.; Nukui, T. (1979) Acute Inhalation Toxicity Study of NP

- 55 on Rat.

(Unpublished study received Aug 4, 1980 under 0G2396; prepared by Nippon Soda Co., Ltd., Japan, submitted by BASF Wyandotte Parsippany, N.J.; CDL:099536

- E).

41510606 Marroquin, F. (198 3) Two Generation Reproduction Study of NP

- 55 in Rats: Lab Project

Number: 449

- 009: BASF 84

- 0068. Unpublished study prepared by International Research and Development Corp. 377 p.

43366401 Grossi, I. (1994) Determination of Homogeneity and Stability of N P

- 55 (Sethoxydim) in

Dietary Mixtures: Lab Project Number: 449/021: 94/5111. Unpublished study prepared by International Research and Development Corp. 75 p.

### 50 

## A PPENDIX A. SLUA Summary Table for Sethoxydim

Date: May 19, 2014

Screening Level Estimates of Agricultural Uses of Sethoxydim (121001)

Sorted Alphabetically (Reporting Timeframe: 2004

- 2012)

Crop l bs. A.I. Percent Crop Treated
Average Maximum

1 Alfalfa 10,000 <1 <2.5

2 Almonds 3,000 <2.5 5

3 Apples <500 <1 <2.5

4 Apricots <500 <2.5 10

5 Artichokes <500 <2.5 <2.5

6 Asparagus 1,000 5 10

7 Beans, Green 6,000 10 15

8 Blueberries 2,000 5 10

9 Broccoli 1,000 <2.5 5

10 Brussels Sprouts* <500 N/A N/A

11 Cabbage 1,000 5 10

12 Caneberries <500 5 10

13 Canola 1,000 <2.5 <2.5

14 Cantaloupes 2,000 5 25

15 Carrots <500 <2.5 5

16 Cauliflower <500 5 10

17 Celery <500 <2.5 <2.5

18 Cherries <500 <2.5 <2.5

19 Corn 3,000 <1 <2.5

20 Cotton 4,000 <1 <2.5

21 Cucumbers 1,000 5 10

22 Dry Beans/Peas 100,000 30 35

23 Eggplant <500 5 10

24 Fallow <500 <1 <2.5

25 Garlic <500 <2.5 5

26 Grapefruit <500 <2.5 <2.5

27 Grapes 4,000 <2.5 5

28 Hazelnuts <500 <2.5 <2.5

29 Lettuce 1,000 <2.5 10

30 Oats <500 <1 <2.5

### 51

Crop l bs. A.I. Percent Crop Treated
Average Maximum

31 Onions 3,000 5 15

32 Oranges 8,000 <2.5 5

33 Peaches <500 <1 <2.5

34 Peanuts 10,000 5 10

35 Pears <500 <2.5 <2.5

36 Peas, Green 3,000 5 15

37 Pecans 1,000 <2.5 <2.5

38 Peppers 1,000 5 15

39 Pistachios <500 <1 <2.5

40 Plums/Prunes <500 <1 <2.5

41 Potatoes 4,000 <2.5 5

42 Pumpkins 1,000 5 10

43 Soybeans 30,000 <1 <2.5

44 Spinach <500 <2.5 <2.5

45 Squash 1,000 5 10

46 Strawberries <500 <2.5 10

47 Sugar Beets 6,000 <2.5 5

48 Sunflowers 9,000 5 10

49 Sweet Corn 2,000 <2.5 5

50 Tobacco 2,000 5 10

51 Tomatoes 2,000 <2.5 5

52 Walnuts 1,000 <2.5 5

53 Watermelons 4,000 10 20

54 Wheat 1,000 <1 <2.5

All numbers rounded. <500: indicates less than 500 pounds of active ingredient. <2.5: indicates less than 2.5 percent of crop is treated. * CA data only ; 80% or more of U.S. acres are in California

SLUA data sources include:

USDA

- NASS (United States Department of Agriculture's National Agricultural Statistics Service)
Private Pesticide Market Research California Department of Pesticide Regulation (DPR) Pesticide Use Reporting (PUR) database

These results reflect amalgamated data developed by the Agency and are releasable to the public.

### 52 

## APPENDIX B. Sethoxydim Ecotoxicity Data

Toxicity to Terrestrial Organisms

Avian Toxicity

Table B

- 1. Acute Oral Toxicity of Sethoxydim to Birds

Species % ai LD 50 (mg a.i./kg

- bw) Toxicity

Category MRID No.

Author, Year Study

Classification

Mallard duck ( Anas platyrhynchos ) 97.3 > 2510 1 Practically

non

- toxic 000 42813

Fink, 1979 Acceptable

1 No mortality , or behavioral abnormalities at test concentrations tested. There was a reduction in feed consumption at the 1000 and 1590 mg a.i. /kg

- bw dose levels

.


### Table B

- 2. Subacute Dietary Toxicity of Sethoxydim to Birds

Species % ai LC 50 (ppm a.i.) 1 Toxicity

Category MRID No.

Author, Year Study

Classification Northern bobwhite quail ( Colinus virginianus ) 97.3 >5620 2 Practically

non

- toxic 000 42814

Fink, 1979 Acceptable

Mallard duck ( Anas platyrhynchos ) 97.3 >5620 3 Practically

non

- toxic 000 72862

Fink, 1979 Acceptable

1 Test organisms observed an additional three days while on untreated food.

2 There were no mortalities in any treatment concentrations that were tested; however, there were four mortalities (8%) in
the control. The mortalities in the control were believed to be due to toe picking. Two other groups also showed evidence of toe and nostril picking, which may have affected the average body weight gain observed. All other birds were normal in both appearance and beh avior during the test period.

3 No mortality or overt toxicity occurred in any concentration that was tested , including the control

.


### Table B

- 3. Chronic Toxicity of Sethoxydim to Birds

Species % ai NOAEC/LOAEC (ppm a.i.) Endpoints MRID No. Author, Year Study

Classification Bobwhite Quail ( Colinus virginianus ) 96.8 1000/≥1000 1 No treatment related effects 44003401 Munk, 1996 Acceptable

Mallard duck ( Anas platyrhynchos ) 96.8 <100/100 2 Number of normal hatchlings 44003402

Beavers, 1996 Supplemental

Mallard duck 94.8 466/953 3 Proportion of number of hatchlings to live 3

- week (21

- d) viable embryos 48000901 Zok, 2009 Acceptable

1 No treatment related mortalities or signs of overt toxicity were observed at any test concentration when compared to the control

group . Adult females from all three test concentrations laid fewer eggs than the control birds; however, this difference was not considered treatment related since the response was not dose dependent.

2 No NOAEC was observe d as t here were significant reductions in the number of normal hatchlings at the 100 and 500 ppm concentrations and a 30% reduction in normal hatchlings at the 1000 ppm level when compared to the control were observed.
The 100 ppm was the lowest test conc entration that was tested.

3 No treatment related mortalities were observed, although one (1) mortality was observed in the 500 ppm a.i. dose level withou t prior clinical signs of toxicity.

### 53 Mammalian Toxicity

Table B

- 4. Acute and Chronic Toxicity of Sethoxydim to Mammals

Species % ai Test

Type Toxicity Value Most Sensitive Endpoints MRID No.

Author, Year Study

Classification Laboratory rat ( Rattus norvegicus ) (Sprague

- Dawley) 94

- 99 Acute
Oral LD 50 = 2676 (F);

3125 (M) mg a.i./kg

- bw 1 Mortality 00045847
Nishibe & Souma, 1979 Acceptable

Laboratory rat (Sprague

- Dawley) 18 Acute
Oral LD 50 = 4385 (F);

5000 (M) mg a.i./kg

- bw 2 Mortality and clinical signs of toxicity 2 00046326

Gelbke, et al.

, 1980 Acceptable

Laboratory rat ( Sprague

- Dawley ) 94

- 99 Acute
Inhal. LC 50 (4 hrs) = 6.03 (M); 6.28 (F) mg/L 3 No mortality, some clinical signs of toxicity were
observed 3 00045849

Nishibe & Nukui, 1979 Acceptable

Laboratory rat (Charles River CD ) 94

- 99 2

- gen

repro. NOAEC/LOAEC =

600/3000 ppm (30/150 mg/kg/day) 4 Offspring, developmental: tail

abnormalities in F 1a and F 1b offspring; malformations described as threadlike tail, no anal opening, malformed hindlimb, malpositioned kidneys, cleft lip, cleft palate,
and microphthalma

. No Systemic or Reproductive
effects observed

. 4 41510606
&
43366401 Marroquin

, 198 3
& Grossi,
1994 Acceptable

1 Signs of toxicity observed included: a taxia, sedation, hypotonia, lacrymation, salivation, tremor, paralysis, fall of body temperature,
and urine incontinence diarrhea.

2 Signs of toxicity observed included: Dyspnea, apathy, spastic gait, and poor general state were symptoms in all dosage groups. Abnormal position, staggering, piloerection, and salivation were observed in the four (4) highest dosage groups; atoni a, pain reflex absent, narcotic like state, and exciccosis were present in the three (3) highest dosage groups

. At necropsy, dead animals showed heard dilatation, acute congestive hyperemia with atonic, diarrheaic intestine; an d sacrificed a nimals showed several cases of adhesions of forestomach to liver, spleen, peritoneum with thickened forestomach and focal thickenings.

3 The exposure was 4 hours in duration. No mortalities occurred in any treatment or control groups. Lacrymation and s alivation were observed at 2 hours, lasting to 4 hours after inhalation exposure in both experimental and vehicle control groups. Body weigh ts in all groups decreased at 4 hours, but recovered afterwards, with stunted recovery in experimental animals. No other toxic effects were
observed.

4 No dose

- related gross or microscopic lesions, or developmental variations (cannibalism complicated the evaluation). No parental toxicity was observed at either the mid or high

- dose, and there were problems with the feed formulation stability, homogeneity, and dose concentration that made it impossible to ascertain the actual doses used. However, additional information was submitted by the registrant, and the highest dose used in the reproduction study was 3000 ppm administered in the diet, or approx. 150 mg/kg/d ay. This
is about one

- fourth the gavage LEL of 650 mg/kg/day in a rat developmental toxicity study (Project No. 92

- 3826)

– a maternally toxic dose that had not effect on reproduction. Taking the differences in dosing regimens and durations, HED presented in their Se ptember 1994 memo that the 3000 ppm dose was defined as a free

- standing NOEL, and the reproductio n study was upgraded to CORE

minimum.


### Terrestrial Invertebrate Toxicity

Table B

- 5. Acute Contact Toxicity of Sethoxydim to Terrestrial Invertebrate s

Species % ai LD 50 (μg/bee) 1 Toxicity Category MRID No. Author, Year Study

Classification Honey bee ( Apis mellifera ) 98.9 10 Moderately toxic 41510607 Nippon Soda Co., 1981 Acceptable

1 Mortality was reported at 24 hours, and not 48 hours. No mortalities were observed for the technical material or acetone con trol in the acute contact (topical application) test method. Information for other exposure routes for adult honey bees is availab le, as t he study conducted exposure to adult bees via spray and oral exposure routes 10% mortality was observed via the spray exposure r oute, and 5% mortality was observed via the oral exposure route at 24 hours, respectively , but are not a guideline quali ty study

. MRID
00042817 for honey bees are pre liminary trials for this study.

### 54 Toxicity to Terrestrial Plants

Table B

- 6. Non

- target Terrestrial Plant Seedling Emergence Toxicity (Tier I)

Species % ai Dose (lbs a.i./A) % Response and

Endpoint Affected MRID No.

Author, Year Study

Classification

Monocot

- Corn 50.5 0.47 15 (phytotoxicity)

44204801 Maggi, 1993 Supplemental Monocot

- Ryegrass 50.5 0.47 44 (emergence) 62.5 (phytotoxicity)

Monocot

- Onion 50.5 0.47 0 (no effect)

Monocot

- Oat 50.5 0.47 15 (phytotoxicity)

Dicot

- Root Crop

- Radish 50.5 0.47 0 (no effect)

Dicot

- Soybean 50.5 0.47 0 (no effect)

Dicot

- Cabbage 50.5 0.47 15 (phytotoxicity)

Dicot

- Tomato 50.5 0.47 0 (no effect)

Dicot

- Cucumber 50.5 0.47 0 (no effect)

Dicot

- Lettuce 50.5 0.47 0 (no effect)



### Table B

- 7 . Non

- target Terrestrial Plant Seed Germination/Seedling Emergence Toxicity (Tier II) 1

Species % ai EC 25 /NOAE C (lbs a.i./A) Endpoint Affected MRID No.
Author/Year Study

Classification

Monocot

- Corn 50.5 0.418/0.235

D ry weight

43614603 Maggi, 1994 Supplemental Monocot

- Oat 50.5 0.280/0.059

D ry weight

Monocot

- Ryegrass 50.5 0.078/0.059

P hytotoxicity, dry weight

1 For Tier II seed germination and seedling emergence, ryegrass is most sensitive monocot species tested. Dicot species were not tested. Endpoints were updated using a continuous program, Nuthatch in 2005; most sensitive species was ryegrass EC 25 = 0.078 l b a.i./A (0.021

- 0.28); EC 50 = 0.16 lb a.i./A (0.033

- 0.044); NOAEC = 0.059 lb a.i./A (based on Williams test); slope = 2.21, std. err. 0.873.



### Table B

- 8 . Non

- target Terrestrial Plant Vegetative Vigor Toxicity (Tier II)

Species % ai % Response and Endpoint
Affected MRID No.
Author/Year Study

Classification

Monocot

- Ryegrass 95.4 0.029/0.038 1 weight

41885906 Chetram, 1991 Supplemental Monocot

- Onion 95.4 NOAEC = 0.5

Dicot

- Root Crop

- Carrot 95.4 NOAEC = 0.5

Dicot

- Soybean 95.4 NOAEC = 0.5

Dicot

- Lettuce 95.4 NOAEC = 0.5

Dicot

- Tomato 95.4 NOAEC = 0.5

Dicot

- Cabbage 95.4 NOAEC = 0.5

Dicot

- Cucumber 95.4 NOAEC = 0.5

1 EC 25 = 0.029 lb a.i./A (0.023

- 0.037); EC 50 = 0.038 lb a.i./A (0.033

- 0.044); NOAEC = 0.025 lb a.i./A based on Williams test; Slope = 5.75, std. err. = 1.21

### 55

Table B

- 9 . Summary of New Vegetative Vigor Toxicity Data , Tier II parameters by species

– monocot species only 1

Species Endpoint NOAEC (lbs a.i./A) EC 05

(lbs a.i./A) EC 25

(lbs a.i./A) EC 50

(lbs a.i./A) Slope

Corn ( Zea mays ) Dry weight (g) 0.0133 0.0079 0.019 0.036 2.52

Shoot Length (mm) 0.0133 0.021 0.039 0.060 3.63

Survival 0.0384 0.046 0.070 0.093 5.42

Oat (A vena sativa ) Dry weight (g) 0.0303 0.015 0.044 0.095 2.02

Shoot Length (mm) 0.0303 0.022 0.070 0.16 1.94

Survival 0.0649 0.084 0.18 0.30 2.99

Ryegrass ( Lolium perenne ) Dry weight (g) 0.00276 0.0025 0.0086 0.020 1.80

Shoot Length (mm) 0.0061 0.0028 0.013 0.038 1.46

Survival 0.0303 0.029 0.057 0.090 3.31

1 MRID 47691704, Bergfield 2008; Supplemental; Poast ® (BAS 562 05 H) was the formulation that was tested

. 

### Guidelines call for the vegetative vigor and seedling emergence studies to be conducted with the TEP. The vegetative vigor study was supplemental since it was not tested with TEP. No valid Tier II seedling emergence plant study was submitted. Seedling emergence data is needed to assess non

- target plants to Sethoxydim runoff exposure.

Toxicity to Aquat ic Organisms

Aquatic Vertebrate Toxicity

Table B

- 10

. Acute Toxicity of Sethoxydim to Freshwater Fish

Species % ai 96

- hour LC 50 (ppm a.i.) Toxicity

Category MRID No.

Author, Year Study

Classification Rainbow trout, ( Oncorhynchus mykiss ) 97.3 170 ( a.i. nominal ) 1 Practically

non

- toxic 000 42815

Seminara et al

. , 1979 Acceptable

Rainbow trout 19.3 1.2 ( a.i. measured) 6.2 (product) 2 Moderately

toxic 41885902

Bowman & Howell , 1991 Acceptable

Bluegill sunfish, ( Lepomis macrochirus ) 97.3 265 ( a.i. nominal) 3 Practically

non

- toxic 00072863

Seminara et al ., 19 80 Acceptable

Bluegill sunfish 19.3 1.6 ( a.i. measured) 8.3 (product) 4 Moderately

toxic 4188590 1

Bowman & Howell , 1991 Acceptable

Fathead minnow ( Pimephales promelas ) 19.6 1.58 (a.i. measured) 5 Moderately
toxic 47691701

Aufderheide, 2009 Acceptable

1 Test concentrations were reported as nominal of test material, the active ingredient. Behaviors/sublethal effects noted included being irritated (three highest test concentrations

– 56, 100 and 180 mg/L ), erratic swimming, dark discolored pigment, and labored respiration in the highest test concentration (180 mg/L).

2 Effects included mortality, dark discoloration, surfacing, fish on bottom of test chamber, vertical orientation, flared gills , loss of equili brium, quiescence, and/or labored respiration observed in all test concentrations, except the lowest. Mortality was 100% within 48 and 24 hours, respectively in the 1.7 and 2.7 mg/L test concentrations (the two highest test concentrations). If the test

c oncentration was converted to total product LC 50 = 6.2 mg product/L (reported in RED); however, the DER reports the endpoint

as mean

- measured concentrations and that the nominal concentrations were adjusted for purity ; 95% CI = 1.0

- 1.7 mg/L; NOEC = 0.21 mg /L ; slope = 16 ).

3 Test concentrations were reported as nominal of technical material, active ingredient. In the highest test concentration (560 mg/L) 100% mortality was observed. In the second highest test concentration, 320 mg/L, observed behaviors /sub lethal effects included: quiescent, surfacing, sounding, dark discolored pigment, slow respiration, slurping air, irregular and labored resp iration.

4 Effects observed included mortality, dark discoloration, surfacing, fish on bottom of test chamber, twitching, loss of equili brium, vertical orientation, excitable, and/or labored respiration, observed in all but the lowest test concentration. If the tes t
concentration was converted to total product LC 50 = 8.3 mg product/L (reported in RED); however, the DER reports the endpoint

as mean

- measured concentrations and that the nominal concentrations were adjusted for purity; 95% CI = 0.91

- 2.3 mg/L; NOEC

= 0.1 8 mg/L ; slope = 12 )

. 5 In the highest test concentration (10.6 mg a.i. /L) 100% mortality was observed. In the remaining second and third highest test

### 56

concentrations (6.10 and 3.57 mg a.i /L, respectively) observed sublethal effects included: loss of equili brium, discoloration, surfacing and lying on the bottom of the test chamber. Adjusted for purity (95% CI = 1.20

- 2.08 mg a.i./L; NOAEC = 0.41 mg a.i./L) ; equivalent to 8.04 mg formulation/L (95% CI = 6.1

- 10.6 mg formulation L ; NOAEC = 2.09 mg formulation/L )

– not adjusted for purity. Poast ® (BAS 562 05 H) was the formulation that was tested.



### Table B

- 1 1

. Chronic Toxicity of Sethoxydim to Freshwater Fish

Species % ai NOAEC /LOAEC (ppm a.i.) Endpoints MRID No. Author, Year Study

Classification

Fathead minnow ( Pimephales promelas ) 94.8 4 .86/9.59 1 Post

- hatch survival & standard length 47691702

Aufderheide, 2009 Acceptable

Fathead minnow 19.6 0.230/0.474 2 Standard length

, wet weight & post

- hatch
survival 47691703

Aufderheide, 2009 Acceptable

1 T ime

- weighted average (TWA) test concentrations were u sed

. Post hatch survival and standard length were significantly reduced in the highest test concentration compared to the negative control

. 2 Time

- weighted average (TWA) test concentrations were used ; P oast ® (BAS 562 05 H) was the formulation that was tested

. The

m ost sensitive endpoints were standard length and wet weight; additionally post

- hatch survival was also reduced in the highest
treatment level as only one juvenile fish survived to test termination . Based on this, the highest treatment level was excluded
from the statistical analysis on the effect on growth of juvenile fish due to the treatment

- related effect on survival. Significant reductions on both length and wet weight were present in the second highest test concentration 0.474 mg a.i./L level compared to the negative control; whereas the 0.934 mg a.i./L level was excluded from growth analysis due to the significant effect on
survival.



### Table B

- 1 2

. Acute Toxicity of Sethoxydim to Es tuarine/Marine Fish

Species % ai 96

- hour LC 50 (ppm a.i.) Toxicity

Category MRID No.

Author, Year Study

Classification Sheepshead minnow ( Cyprinodon variegatus ) 97.8 >145.8 (measured) Practically

non

- toxic 42315101

Ward & Boeri , 1992 Acceptable

Sheepshead minnow 18.0 3.5 (a.i. , nominal) 19.4 (product, nominal) Moderately to Slightly toxic 41510602

Ward & Boeri , 1989 Acceptable

1 There was 100% mortality observed in the test concentrations > 4.5 mg/L. Sublethal effects observed included loss of equilibrium and change in behavior (surfacing) during the test. If the concentration was converted to total product 96h LC50 = 19.4 mg product/L (reported in RED); however, the DER reports the endpoi nt as “nominal concentrations of the active ingredient;” 95% CI = 2.7

- 4.5 mg a.i./L nominal; NOEC = 2.7 mg a.i./L ; based on survival).



### Table B

- 1 3

. Chronic Toxicity of Sethoxydim to Estuarine/Marine Fish 1

Species % ai NOAEC /LOAEC (ppm a.i.) Endpoints MRID No. Author, Year Study

Classification Sheepshead minnow ( Cyprinodon variegatus ) 40 .7 98/>98 No effects 43614601
Graves et al. , 1995 Supplemental

1 A formulated product Poast 3 .5EC (Reg. # 7679

- 129) was used; the study was supplemental as a LOAEC was not determined in this study.



### Aquatic Invertebrate Toxicity

Table B

- 1 4 . Acute Toxicity of Sethoxydim to Freshwater Aquatic Invertebrates

Species % ai 48

- hour E C 50 (ppm a.i.) Toxicity

Category MRID No.

Author, Year Study

Classification

Waterflea ( Daphnia magna ) 97.3 78 .1 (nominal) 1 Slightly toxic 000 42816 Morrissey et al. , 1979 Acceptable

Waterflea 19.3 2.6 (a.i., m ean

- measured ) 13.5 (product, measured) 2 Moderately to Slightly
toxic 41885903

Blasberg et al. , 1991 Acceptable

1 Dose response slope is 4.73725

2 There was 100% immobility observed in the two highest test concentrations, 4.6 and 8.9 mg/L after 4 hours. In the mid test concentration, 2.4 mg/L, immobility and daphnids were observed on the bottom

. If endpoint was converted to total product E C 50 =

### 57

13.5 mg product/L (reported in RED); however, the DER reports the endpoint as measu red concentrations; 95% CI = 2.0

- 3.3 mg/L

– mean

- measured; NOEC = 1.1 mg/L ; slope = 7.4 ).


### Freshwater Aquatic Invertebrates Chronic Toxicity No chronic freshwater aquatic invertebrate studies are available for sethoxydim.



### Table B

- 15 . Acute Toxicity of Sethoxydim to Estuarine/Marine Aquatic Invertebrates

Species % ai 48 /96

- hour EC/ LC 50 (ppm a.i.) Toxicity Category MRID No. Author, Year Study

Classification Eastern oyster (embryo

- larvae) ( Crassostrea virginica ) 94.5 > 109 ( mean

- measured) Practically non

toxic 42537401

Lin t ott, 1992 Acceptable

Eastern oyster 20.4 0.9 (a.i. , nominal) 4.4 (product, nominal) 1 Highly toxic to Moderately toxic 41607207

Ward & Boeri , 1990 Acceptable

Mysid ( Americamysis bahia ) 97.8 >141.8 ( mean

- measured) Practically non

toxic 42315102

Ward & Boeri , 1992 Acceptable

Mysid 18.0 0.8 (a.i., nominal) 4.4 (product, nominal) Highly toxic to Moderately toxic 4151 06 04

Ward & Boeri , 1989 Acceptable

1 If the concentration was converted to total product 48h E C50 = 4.4 mg product/L (reported in RED); however, the DER reports the endpoint as “nominal concentrations of the active ingredient;” 95% CI = 0.6

- 1.0 mg a.i./L nominal).

2 There was 100% mortality observed in the test concentrations ≥ 1.1 mg/L , and no sublethal effects were observed in any test
concentration. If the concentration was converted to total product 96h LC50 = 4 .4 mg product/L (reported in RED); howev er, the DER reports the endpoint as “nominal concentrations of the active ingredient;” 95% CI = 0 .7

- 1.1 mg a.i./L nominal; NOEC = 0 .7 mg a.i./L; based on survival).



### Table B

- 1 6

. Chronic Toxicity of Sethoxydim Estuarine/Marine Aquatic Invertebrates

Species % ai 21

- d NOAEC /LOAEC (ppm a.i.) Endpoints MRID No. Author, Year Study

Classification Mysid ( Americamysis bahia ) 4 3.1 15.1 /30.2 (product)
6.5 /13 ppm a.i. Survival & Length 1 4361460 2

Boeri et al.

, 1995 Supplemental

1 Erratic swimming and/or lethargy were noted in the two highest test concentrations (56 and 113 mg a.i./L) until complete mortality occurred on days 4 and 14 for each group, respectively. Other endpoints affected included reproduction (neonates produced), and weight (dry and wet). The study was classified as supplemental because it was conducted with an end

- use product (EP) and not technical grade (TGAI) test material as required by CFR 158.490.


### Aquatic Plant Toxicity

Table B

- 1 7 . Toxicity of Sethoxydim to Aquatic Plants

Species % ai EC 50 (mg a.i./L) NOAEC

(mg a.i./L) Endpoints MRID No. Author, Year Study

Classification

Vascular Plants

Duckweed ( Lemna gibba ) 99.8 14d EC 50 >0.281 14d NOAEC

= 0. 281 No significant

effects 1 43614605

Thompson et al. , 1994 Acceptable

Reed M annagrass ( Glyceria maxima ) 19.3 21d EC 50 = 0.21 21d NOAEC

= 0.093 Growth rate

based on total leaf length 2 48000902

Knauert, 2009 Acceptable

Non

- Vascular Plants

Green algae ( Selenastrum capricornutum ) 99.8 120 hr EC 50 >0.302 120 hr

NOAEC =
0.302 No effects 43614607 Thompson et al. , 1994 Acceptable

Marine diatom ( Skeletonema costatum ) 99.8 120 hr EC 50 >0.250 120 hr

NOAEC =
0.250 No effects 43626101 Thompson et al. , 1994 Acceptable

### 58

Species % ai EC 50 (mg a.i./L) NOAEC

(mg a.i./L) Endpoints MRID No. Author, Year Study

Classification

Freshwater diatom ( Navicula pelliculosa ) 99.8 120 hr EC 50

> 0.266 120 hr

NOAEC =
0.266 No effects 43614606 Thompson et al. , 1994 Acceptable

Blue

- green algae ( Anabaena flos

- aquae ) 99.8 120 hr EC 50

> 0.303 120 hr

NOAEC =
0.303 No significant

effects 3 43614608

Thompson et al.

, 1994 Acceptable

1 Some necrosis, chlorosis, and dead plants were noted in the control and treatment groups. However, a clear dose response was not noted for any one symptom.

2 The endpoints were based on 21

- day results, in addition to the most sensitive endpoint of total leaf length, growth rate based on dry weight also showed effects, and the resulting EC50 and NOAEC values were 2.9 and 0.093 mg a.i./L, respectively. The perce nt growth inhibition of total leaf length in treated culture as compared to the control ranged from 10 to 95%. Rhizome developm ent was affected and plants showed moderate to strong necrotic symptoms.

3 Replicate C of the 0.039 mg a.i./L treatment group had 95% less cells than the other two replicates. The results of this replicate were not included in the analysis.

### 59



## APPENDIX C

. Sethoxydim Incidents

A search for ecological incidents related to sethoxydim use, conducted on January 23, 201 5, yielded four (4) incidents; two (2) involving aquatic animals and two (2) terrestrial plants

, which are summarized below.

Table C

- 1. Sethoxydim Incidents, as Reported in the EIIS Database

Incident ID # State, County Magnitude Year Description Legality Certainty

I011716

- 002 AZ, Maricopa Unknown 2001 A crop

- dusting plane by pilot John Pew, misdirected spray suffocated dozens of White Amur grass carp ( Ctenpharyngondon
idella ) . The pilot was to spray Thiodan and Checkmate over a cotton field to kill the common whitefly, The fish kill cost the Salt River Project (SRP) $4,000 to replace the fish, but, the pilot was fined $113 plus $182 for spraying the house.

Endosulfan is much more toxic to fish than is sethoxydim and was likely the primary cause of the fish mortality. It is possible, however, that sethoxydim also contributed to the toxicity to the fish. Misuse (Accidental) Possible

I000232

- 001 USA 300 1992 According to the report a pond collected water from a large watershed that drained 104 acres of farmland where cotton (40 yards away) and peanuts (60 yards away) were being grown. The cotton had been treated with Pix (growth regulator) and the peanuts had
been treated with Poast

- Plus Herbicide and Lorsban 15G Granular
Insecticide 8

- 10 days prior to an alleged fish kill (Bluegill and Crappie) . Two inches of rain fell one hour after the Lorsban application. It was believed that chlorpyrifos was responsible fo r the observed incident. Four pond water samples were collected and analyzed for chlorpyrifos one week after the fish kill was reported. Presence of chlorpyrifos was revealed. The product label states that drift or runoff from treatment areas may be hazard ous to aquatic organisms in neighboring aquatic sites.
While chlorpyrifos is probably the primary cause of this fish kill, It is also possible that mepiquat chloride and sethoxydim contributed to the toxicity observed in this incident. Registered Use Possible

I021485

- 016 ID, Cassia 100% (193 acres) 2009 An application of the products Huskie (a.i. pyrasulfotole,

bromoxynil octanoate and bromoxynil heptanoate) and Hi Yield (a.i. sethoxydim) onto 193 acres of winter wheat in Cassia County, ID allegedly stunted the crop. Registered Use Possible

I018428

- 016 CA, Tulare 20% of crop yield 2006 An aerial application of the prod uct (Poast) resulted in damage to

water melon fruits and foliage. The application was made at twice the label rate. Application rate was listed as 51.2 oz/A. Misuse (Intentional) Possible

### 60

Uncertainties Related to the Use of Incident Information from the Ecological Incident Information System

Incident data are used in risk assessments to provide evidence that the risk predictions from the screening level assessment are supported by actual effects in the field. Incident reports submitted to EPA since approximately 1994 have been tracked by assignment of incident numbers in an Incident Data System (IDS), microfiched, and then entered to a second database, the Ecological Incident Informa tion System (EIIS). Additio nally, there is an on

- going effort to enter information to EIIS on incident reports received prior to establishment of current databases. Incident reports are not received in a consistent format ( e.g ., states and various labs usually have their own
format s), may involve multiple incidents involving multiple chemicals in one report, and may report on only part of a given inciden t investigation ( e.g ., residues).

Incidents entered into EIIS are categorized into one of several certainty levels regarding the likelihood that a particular pesticide is associated with the incident: highly probable, probable, possible, unlikely, or unrelated. In brief, “highly probable” incid ents usually require carcass residues and/or clear circumstances regarding the exposure. “Probable” incidents include those where residues were not available and/or circumstances were less clear than for “highly probable.” “Possible” incidents include those where multiple chemicals may have been involved and it is not clear what the contribu tion was of a given chemical. The “unlikely” category is used, for example, where a given chemical is practically nontoxic to the category of organism killed and/or the chemical was tested for but not detected in samples. “Unrelated” incidents are those that have been confirmed to be not pesticide

- related.

Incidents entered into the EIIS are also categorized as to use/misuse. Unless specifically confirmed by a state or federal a gency to be misuse, or there was very clear misuse such as intentional baiti ng to kill wildlife, incidents are not typically considered misuse.

The number of documented kills in EIIS is believed to be a small fraction of total mortality caused by pesticides. Mortality incidents must be seen, reported, investigated, and have in vestigation reports submitted to EPA to have the potential for entry into the database. Incidents often are not seen, due to scavenger removal of carcasses, decay in the field, or simply because carcasses may be h ard to see on many sites and/or few people are systematically looking. Poisoned animals may also move off

- site to less conspicuous areas before dying. Incidents may not get reported to appropriate authorities capable of investigating the incident for a variety of reas ons including the finder may not know of the importance of reporting incidents, may not know who to call, may not feel they have the time or desire to call, or may hesitate to call because of their own involvement in the kill. Incidents reported may not get investigated if r esources are limited or may not get investigated thoroughly, with residue analyses, for example. Also, if kills are not reported and inve stigated promptly, there will be little chance of documenting the cause, since tissues and residues may deteriorate quickly. Reports of investigated incidents often do not get submitted to EPA, since reporting by states is voluntary.

Furthermore, the database relies heavily on registrant

- submitted incident reports, and registrants are currently only required to submit
detaile d information on ‘major’ ecological incidents, while ‘minor’ incidents are reported aggregately.

### 61

Based on the 40 CFR (§159.184 Toxic or adverse effect incident reports), an ecological incident is considered ‘major’ if any of the following criteria are me t:

Fish or wildlife : (A) Involves any incident caused by a pesticide currently in Formal Review for ecological concerns.

(B) Fish: Affected 1,000 or more individuals of a schooling species or 50 or more individuals of a non

- schooling species.

(C) Bird s: Affected 200 or more individuals of a flocking species, or 50 or more individuals of a songbird species, or 5 or more individuals of a predatory species.

(D) Mammals, reptiles, amphibians: Affected 50 or more individuals of a relatively common or herd ing species or 5 or more individuals of a rare or solitary species.

(E) Involves effects to, or illegal pesticide treatment (misuse) of a substantial tract of habitat (greater than or equal to 10 acres, terrestrial or aquatic).

Plants : (A) The effect is alleged to have occurred on more than 45 percent of the acreage exposed to the pesticide.

All other ecological incidents are considered ‘minor’ and only need to be aggregately reported. ‘Minor’ incidents reported b y the registrants are not included in the EIIS database. Therefore, for example, an incident could affect 900 fish, 150 birds, 45 mammals, and 40% of an exposed crop and not be included in the EIIS database [unless is it reported by a non

- registrant ( e.g ., an incident submitted by
a state ag ency

– which are not systematically collected)]. Therefore, because the number of documented kills in EIIS is believed to be a small fraction of total mortality caused by pesticides, absence of reports does not necessarily provide evidence of an absenc e o f incidents.

### 62



## A PPENDIX D . SIP & STIR Inputs and Outputs for Sethoxydim

SIP Inputs/Outputs

### 63

STIR Inputs/Outputs